Caltech supplemental essays
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Caltech Supplemental Essays 2024-25

Quick Facts- Caltech Essays

  • Caltech acceptance rate:  3%—U.S. News ranks Caltech as a most selective school.
  • Caltech supplemental essays requirements:
    • 1 Academic essay
    • 4 Short answer essays
  • Caltech application: The Caltech application can be submitted via the Common App, Apply Coalition, Powered by Scoir, or through Questbridge. Make sure to check all of the Caltech application requirements. 
  • Caltech supplemental essay tip: Your responses to the Caltech essay prompts are your chance to show your love of STEM. Use the opportunity to show how you would thrive in a STEM-focused environment. 

What are Caltech’s supplemental essays?

The Caltech supplemental essays are listed on the Common App website. You can also find the Caltech supplemental essays listed on Caltech’s website, alongside brief explanations of each prompt. 

Required Caltech supplemental essays and short answer questions:

1. Caltech has a rigorous core curriculum and students don’t declare a major until the end of their first year. However, some students arrive knowing which academic fields and areas already most excite them, or which novel fields and areas they most want to explore.

If you had to choose an area of interest or two today, what would you choose? Why did you choose your proposed area of interest? If you selected ‘other’, what topics are you interested in pursuing? (200 words)

2. Regardless of your STEM interest listed above, take this opportunity to nerd out and talk to us about whatever STEM rabbit hole you have found yourself falling into. Be as specific or broad as you would like. (Min: 50 / Max: 150 words)

3. At Caltech, we investigate some of the most challenging, fundamental problems in science, technology, engineering, and mathematics. We are interested in learning more about your engagement with STEM.

Please share two STEM-related experiences:

  • Tell us about a STEM-related experience from the last few years and share how and why it inspired your curiosity. (Min: 100 / Max: 200 words)
  • Tell us how you initially found your interest and passion for science or any STEM topic, and how you have pursued or developed this interest or passion over time. (Min: 100 / Max: 200 words)

4. The creativity, inventiveness, and innovation of Caltech’s students, faculty, and researchers have won Nobel Prizes and put rovers on Mars, but Techers also imagine smaller scale innovations every day, from new ways to design solar cells to 3D printing dorm décor. How have you been an innovator in your own life? (200-250 words)

5. Caltech’s values include respect for a diversity of thoughts and ideas. How have you cultivated this value in your own life? (Min: 50 / Max: 200 words)

Optional Caltech supplemental essays:

1. If there are aspects of your identity that you feel are not captured elsewhere in this application, please provide that information below. (150 words)

2. When not surveying the stars, peering through microscopes, or running through coding marathons, Caltech students pursue an eclectic array of interests that range from speed-cubing, reading, yoga, playing musical instruments and theater arts, to solving puzzles, hiking, painting, and building or inventing new gadgets. We understand that everyone needs an outlet or two. What is a favorite interest or hobby, and why does it bring you joy? (200 words)

3. Did you have a hard time narrowing it down to just one interest or hobby? We understand – Caltech students like to stay busy, too – tell us about another hobby or interest! (150 words)

4. Have you had any extenuating circumstances regarding your coursework (such as limited course selection or disruptions) not described elsewhere in your application? If so, tell us about them here.

You’ll notice that the first thing stated on the Caltech supplemental essays page is that Caltech is “unapologetically STEM.” So, Caltech admissions wants to read all about your STEM-specific experiences. When considering how to write Caltech essays, look first to the “what we look for” page on the Caltech site. This is a cohesive list of what admissions looks for in applicants. 

Notably, the Caltech supplemental essays do not ask students to write a “Why Caltech essay.” However, just because there is no “Why Caltech essay” doesn’t mean that you can’t show the admissions team why you belong at a science and engineering powerhouse like Caltech. So, think of these essays as your chance to show how you’ll contribute to the Caltech community. 

Whenever possible and relevant, reference specific Caltech programs, classes, professors, and organizations that you would take advantage of. The Caltech admissions process extends beyond the admissions office alone. In fact, the Caltech supplemental essays are read directly by faculty. With a 3:1 student to faculty ratio at Caltech, it may not be a surprise that students closely interact with their professors. 

Later in this guide, we will break down each of the Caltech essay prompts in more detail. This should give you an idea of Caltech supplemental essay examples, both required and optional.

How many essays does Caltech require?

Caltech requires students to complete five Caltech essay prompts.

These Caltech essay prompts ask students to reflect on their experiences, interests, and character. You should also use the Caltech essay prompts to discuss your STEM experiences. Prime Caltech supplemental essay examples will encompass who you are within the context of STEM programs. Additionally, you’ll want to show that you’re a motivated, curious, and passionate learner.

Additionally, there are four optional Caltech essay prompts that students can respond to. Caltech stresses that these Caltech essays are optional. We’ll get into specifics later about these optional Caltech essays. This may help you determine if and when to respond to each of the optional Caltech supplemental essays. 

How to Write Caltech Essays

Caltech supplemental essays

So, how do you answer the Caltech supplemental essays?

The five Caltech supplemental essays aren’t necessarily long. They vary in length from 150-250 words. Therefore, in these Caltech essays, you will want to focus on both content and execution in your writing process. As we’ll discuss, each of the Caltech supplemental essays asks students to reflect on a particular experience or interest. 

To maximize your Caltech essays, you’ll want to offer a brief summary of each experience of an event. Then, use the bulk of your essay to reveal how this experience or event influenced your broader character. Specifically, when focusing on how to write Caltech essays, reflect on your STEM experiences. You may want to write about STEM research in your Caltech supplemental essays. The admissions committee should come away from your Caltech supplemental essays with a clear conception of who you are and the kind of community member you would be on the Caltech campus. 

Caltech Essay Prompts #1 

If you had to choose an area of interest or two today, what would you choose? Why did you choose that area of interest? (200 words)

The first of the four required Caltech essay prompts asks applicants to write “why major essays.” Caltech makes it clear that students aren’t expected to know their major. In fact, students actually can’t declare a major until after their first year. So, undecided students shouldn’t stress too much about their choice of major in these “why major essays.” Students are in no way obligated to study the major in which they reference in their why major essays. 

To answer the first of the Caltech supplemental essays, students should reflect on why they want to attend a STEM-forward university such as Caltech. Think about more than just the Caltech ranking and Caltech acceptance rate. What made you first fall in love with STEM? What specific programs are offered at Caltech and nowhere else? Are you planning to go pre med and hoping to study science at one of the best institutions for STEM? Do some research on the Caltech website in order to reference specific details on programs, internships, research, or faculty.  

Think about the “why”

After having decided an area of interest to write about in this Caltech supplemental essay, focus on the “why” part. Successful “why major essays” will explain why you need to study that major in that particular school. They’ll draw from both personal and academic experiences. Students should also discuss how studying this major would influence their future career goals. 

Let’s say you decide to focus on chemistry. You could discuss how your AP Chemistry course challenged your previous understanding of science. Or maybe a specific experiment stands out in your mind as the point when you knew chemistry was for you. Or perhaps it was the teacher that made an impact on your life. Whatever the reason, reference an academic or personal experience that told you this was the major for you. If you can get more specific than just “chemistry,” such as organic or inorganic chemistry, biochemistry, theoretical chemistry, etc., that’s even better.

Reflection Questions for Caltech Essays:

  • Do you choose an area of interest that genuinely excites you?
  • Does your essay talk about Caltech specific programs and offerings?
  • Do you tie your study interest to your future and career goals?

Caltech Essay Prompt #2

Regardless of your STEM interest listed above, take this opportunity to nerd out and talk to us about whatever STEM rabbit hole you have found yourself falling into. Be as specific or broad as you would like. (Min: 50 / Max: 150 words)

The Caltech supplemental essays give you an opportunity to show your interests, academically and otherwise. In this particular essay, you’ll need to show your love of STEM. What STEM topic has got you up at night?

You’ll want to show that you are a curious and motivated student. What STEM-related topic are you studying outside of the classroom? Why has it caught your interest? What makes you so curious about this particular topic? Share your learnings on the subject that has sparked your interest.

You don’t have many words for the second of the Caltech supplemental essays, so you’ll need to be concise with your response. Be sure to be genuine and specific. And, most importantly, have some fun and “nerd out” about your favorite STEM interest!

Reflection Questions for Caltech Essays:

  • Do you clearly specify your STEM interest?
  • Do you show passion and knowledge on the topic?
  • Do you show that you’re a curious and motivated STEM learner?

Caltech Essay Prompts #3

At Caltech, we investigate some of the most challenging, fundamental problems in science, technology, engineering, and mathematics. We are interested in learning more about your engagement with STEM.

Please share two STEM-related experiences:

Tell us how you initially found your interest and passion for science or any STEM topic, and how you have pursued or developed this interest or passion over time. (Min: 100 / Max: 200 words)

Tell us about a STEM-related experience from the last few years and share how and why it inspired your curiosity. (Min: 100 / Max: 200 words)

Similar to the “why major essays,” successful Caltech supplemental essays for this prompt will show applicants’ love of STEM. However, the difference between these two Caltech essay prompts is that the first should focus on a specific area of interest offered at Caltech. This prompt, however, asks students what initially sparked their interest in STEM and to expand upon a particular experience during high school that has continued to nourish this interest. 

For the first part of this prompt, you’ll want to reflect on what started your love of STEM. Was it a particular event, conversation, class, or something else? Were you raised by scientists who had you playing with robots in the sandbox? Whatever it was for you, now’s your opportunity to share it.

In the second part of this first prompt, you’ll need to show how you’ve pursued or developed the topic that has sparked your interest and passion. Are you constantly reading and researching the topic? Do you have a little lab in the garage where you try experiments? Have you attended workshops or camps on the subject matter? Whatever you’ve done to learn more about this topic, share it now.

Now, let’s move on to the second prompt. First of all, we probably don’t have to mention that figuring out how to get into Caltech should start with a passion for STEM (Science, Technology, Engineering, Math) programs. That being said, students will likely have a number of experiences to reference in their Caltech essays. Start by brainstorming some of the most impactful STEM moments of your high school career. 

Are you in the robotics club and spend your free time tweaking your newest room cleaning robot? Or have you just led your team to the finals of your state’s math competition? Did you participate in a STEM summer program? Or, maybe it’s nothing too outwardly dramatic. It could be something as simple as an experiment in biology class that ignited your curiosity. 

Make a list and choose the experience that evokes emotion surrounding choosing STEM. Caltech admissions wants to see serious STEM applicants in these Caltech supplemental essays. Show through your chosen experience that you are passionate and committed to a STEM education.

When writing, you’ll also need to show why you want to further study STEM. How did this experiences shape your future goals and intellectual curiosity? California Institute of Technology seeks students who will pursue their interests, contribute to a thriving intellectual community, and still love learning even when classes get difficult. 

Reflection Questions for Caltech Essays:

  • Does your draft sincerely convey your inspiration, passion, and excitement for STEM?
  • Do you a specific and recent STEM related experience?
  • Do you show how these experiences have affected your future studies?

Caltech Essay Prompts #4

The creativity, inventiveness, and innovation of Caltech’s students, faculty, and researchers have won Nobel Prizes and put rovers on Mars, but Techers also imagine smaller scale innovations every day, from new ways to design solar cells to 3D printing dorm décor. How have you been an innovator in your own life? (200-250 words)

When planning how to write Caltech essays, you may think that you only need to focus on STEM-related topics and experiences. Of course, Caltech admissions shamelessly states that they want to hear about as much STEM topics as possible in students’ Caltech supplemental essays. However, they also look for critical thinkers with the ability to problem solve. This prompt asks applicants to think about times when they had to create their own innovative solutions to problems. 

If you can think of STEM related instances, great. However, if not, don’t stress. Successful Caltech essays responding to this prompt will just show how you creatively found solutions to an issue you were facing. 

Let’s say your doorbell was broken for months. No one in your household seemed too concerned about it, but one day you miss an important package that you’d been looking forward to receiving. You decide to take matters into your own hands and fashion your own doorbell with some tips from the employee at your local hardware store. Problem solved. 

Solving problems

Any version of that hypothetical story will work in this Caltech supplemental essay. There’s a problem that needs to be solved, and you do so. If you’re stuck, try to focus on your strengths. Are you hard-working, creative, motivated, or curious? Highlight these strengths in the examples you come up with for this essay. 

You have to fall within 200-250 words, so you can use multiple anecdotes here. However, keep it focused—limit yourself to one or two topics. Make a list and choose the instances that show your most innovative, creative, and unique solutions to personal problems while highlighting your strengths. 

Reflection Questions for Caltech Essay:

  • Does your essay show that you are innovative and creative?
  • Do you discuss specific examples and solutions that you came up with?
  • Does your essay give Caltech admissions a better picture of who you are and what you would bring to the campus?

Caltech Essay Prompts #5

Caltech’s values include respect for a diversity of thoughts and ideas. How have you cultivated this value in your own life?  (50-200 words)

You might have seen a similar version of the last of the required Caltech supplemental essays. College campuses want diversity and differing perspectives. They expect their students to be open-minded, passionate, and curious (both in and out of the classroom). Therefore, this prompt is your opportunity to share how you have cultivated a respect for thoughts and ideas that may not necessarily be similar to your own.

There are plenty of ways that you can answer this prompt. However, whatever you write on, you’ll want to be specific and genuine. Maybe you’d like to highlight a specific conversation that showed you a new way of thinking. How did it affect you? What did you take from the interaction?

Or perhaps you’ve been around a lot of diversity you’re entire life. Share how your upbringing has shown you to be open-minded to different ways of thinking. You can share a specific anecdote or experience. Avoid being too general when responding to this or any of the Caltech supplemental essays. The more specific and unique to you, the better!

This essay is an opportunity to show admissions what you’ll bring to campus. Remember that they want students who are passionate, but can also be open-minded when faced with differing opinions or perspectives. Indeed, many advances in STEM have come from the collaboration of various, brilliant minds.

Reflection Questions for Caltech Essay:

  • Do you draw on relevant, personal experiences?
  • Is it evident what an impact those experiences have had on who you are today?
  • Do you show how your background affects your worldview or experiences?

Caltech Supplemental Essays: Optional Short Answer Questions

Caltech supplemental essays

On their website, Caltech prefaces these optional essays by saying that they are “optional opportunities to show us more of your personality.” Before even getting into the optional Caltech essay prompts, admissions reiterates that they are in fact optional by stating: “Optional. We Promise.”

Basically, you can choose whether to answer these Caltech essay prompts or not. However, there are certain optional Caltech essay prompts that you should opt to answer if you want your Caltech application to be as competitive as possible. Let’s take a look at these optional Caltech supplemental essays so you can determine which ones you should indeed respond to.

Optional Caltech Essays #1

If there are aspects of your identity that you feel are not captured elsewhere in this application, please provide that information below. (150 words)

If you struggled to fit all of your meaningful, personality-forming experiences and background information into the last Caltech supplemental essay, then this is your opportunity to add more. 

Continuing with our last example in the previous Caltech supplemental essay, let’s say that you wrote about growing up in a fancy restaurant’s kitchen because of your mom’s profession. Maybe in the last essay, you wrote about how you learned to think on your feet in a high-pressure environment, which has made you the decisive person that you are today. You may want to add onto this by talking about the different cultures that you experienced in the kitchen. Did you become close with the sous chef who was from Italy? Did it inspire a gap year or summer trip to Italy that changed your life?

Or maybe you want to talk about a completely different community that has shaped you. Maybe you’ve grown up training ballet in every moment of your spare time, which has built discipline and pushed you to achieve. If you can talk about how a certain community has formed you, and your story will add value to your Caltech application, then answer this prompt. 

However, if you were struggling with the last of the Caltech essay prompts that touched on background and feel as though you have nothing to add, then feel free to skip this essay.  

Optional Caltech Essays #2

When not surveying the stars, peering through microscopes, or running through coding marathons, Caltech students pursue an eclectic array of interests that range from speed-cubing, reading, yoga, playing musical instruments and theater arts, to solving puzzles, hiking, painting, and building or inventing new gadgets. We understand that everyone needs an outlet or two. What is a favorite interest or hobby, and why does it bring you joy? (Max: 200 words)

While the first of the optional Caltech supplemental essays is actually optional, we recommend considering the second of the Caltech essays as required. The goal of this Caltech supplemental essay is to see who you are outside of STEM-related hobbies and interests. While admissions wants to see that you love all things STEM, they also want to learn about your other interests. They understand the importance of having some sort of outlet from academics or work. 

Use this Caltech supplemental essay to talk about a hobby that you haven’t mentioned elsewhere. Basically, don’t just repeat your extracurricular activities. That certainly won’t do anything to help you beat the Caltech acceptance rate and impress admissions. Talk about something that will demonstrate a new skill or interest. Don’t forget to mention why this activity is worth writing about. What impact has it had on your life?

To start writing this essay, make a list of all of your activities. Hone in on the ones that are most important to you. Make sure they haven’t been mentioned elsewhere in your Caltech application. Then, choose the topic that interests you the most. 

Consider the following questions:

  • Which activity elicits the most emotion? 
  • What hobby could you not live without? 
  • Which interest has made an impact on who you are today?

Successful Caltech essays will not only mention the activity but also explain why it brings joy. Feel free to get creative when responding to this prompt. Make sure that admissions can feel your passion for this topic. 

Optional Caltech Essays #3

Did you have a hard time narrowing it down to just one interest or hobby? We understand – Caltech students like to stay busy, too – tell us about another hobby or interest! (150 words)

This is another of the optional Caltech supplemental essays that is definitely optional. No tricks here. If you are a true hobbyist and have various activities that define you, then feel free to take on this Caltech supplemental essay. 

Was your list of interests from the last essay spilling onto multiple pages? Great. Students writing their Caltech supplemental essays shouldn’t skimp on passion. However, these Caltech supplemental essays will have to be more succinct, as you only have 50 words. 

Stay creative, just as you were with your last essay. Show why this activity brings you such joy and how it has been such a formative part of your being. Just be sure to do so concisely. 

Caltech Supplemental Essays: Optional Academic Short Answer Questions

Caltech supplemental essays

The optional academic Caltech supplemental essays are completely optional. Students should only submit Caltech essays for this section if they truly feel the need to. 

There is no word count listed on these Caltech essay prompts, so these Caltech supplemental essays should be concise. This isn’t the time to write a novel. Answer this Caltech supplemental essay prompt succinctly and comprehensively. 

Caltech Essay Prompts #1

Have you had any extenuating circumstances regarding your coursework (such as limited course selection or disruptions) not described elsewhere in your application? If so, tell us about them here.

Successful essays to the previous optional Caltech supplemental essays are creative, captivating, and passionate. These final Caltech supplemental essays don’t need to tick the same boxes. These Caltech essays serve to fill any mysterious gaps in the rest of your Caltech application. 

This Caltech supplemental essay specifically asks you to explain any extenuating circumstances that may be noticeable in the coursework noted in your application. If you’ve had access to all the STEM, AP, and IB courses, then there’s no need to respond to this prompt. However, if you attended a school with limited resources and offerings, then you should mention that here. 

How much does Caltech care about essays?

Through the Caltech essays, the admissions committee gains a glimpse into who you are as a student, peer, scientist, and individual. Keep in mind that they don’t know what you don’t tell them. Look at your application as a whole—including your Common App essay —and think critically about whether you have included as many facets of yourself as you can. Your Caltech application requirements should do more than just check boxes; they should tell your story, showing why you belong at Caltech. 

The Caltech ranking is #9 on U.S. News’ Best National Universities list. With the Caltech ranking so high, it makes sense that the Caltech acceptance rate is 4%. Every applicant will have an above average GPA and impressive extracurriculars. So, the Caltech supplemental essays are a chance to stand out. Successful Caltech supplemental essays will add to students’ application narratives. Planning how to get into Caltech involves thoughtfully and carefully answering the Caltech supplemental essays.  

Beyond the numbers

The Caltech essay prompts seek to understand who you are rather than just what’s on your resume. This demonstrates the value of the Caltech essays. Since Caltech is test-blind until 2025, you should maximize each essay as an opportunity to help the admissions team get to know you. Test blind schools, unlike test-optional schools, don’t want any ACT/SAT test scores submitted. Basically, Caltech won’t even look at standardized test scores. However, they will pay close attention to the Caltech supplemental essays. 

Check out this webinar to make sure you stand out as a STEM applicant. 

Five Tips for Writing Caltech Essays

Writing comprehensive and meaningful Caltech essays doesn’t have to be overwhelming. We’ve compiled our top 5 tips for how to write Caltech essays that impress admissions. 

Five Tips for Writing Caltech Essays: 

#1- Meet the deadlines

This may seem obvious, but there’s no way that you will figure out how to get into Caltech if you don’t submit your Caltech application requirements by the deadlines. The Regular Decision deadline is January 3rd. The Restrictive Early Action deadline is November 1st. Learn more about applying Early Action in our article.

#2- Don’t rush the writing process

Yes, you know you have to write and submit your Caltech essays by the deadline. However, that doesn’t mean that you should be scrambling to brainstorm, draft, edit, and revise your Caltech supplemental essays the night before they’re due. Give yourself time to craft the best Caltech supplemental essays possible.

#3- Carefully choose your topics

This is why it’s important to give yourself plenty of time to write your Caltech supplemental essays. You only have one chance to impress the admissions committee. You should have various topics to choose from after brainstorming. Write essays on the topics that you are most passionate about. 

#4- Get creative

The greatest scientists are extremely creative innovators. Use your essays to creatively write on the topics you’re given. As long as you comprehensively and thoughtfully answer the prompt, a creative writing style will only bolster your Caltech essays.

#5- Ask for help

You certainly don’t have to take on your Caltech essays completely alone. Have someone else look at your completed Caltech essays. While they should check mechanics, also ask them for feedback on what they’ve learned about you through your Caltech essays. When implementing their feedback, maintain your own voice and style. 

Caltech Supplemental Essays — Final Thoughts

The Caltech supplemental essays are a key part of your application. The Caltech acceptance rate is low. Maximizing your admissions odds will take acing every part of the application process, including the Caltech supplemental essays. 

Remember to be clear, concise , and specific while telling authentic stories in your essays. Reference STEM-related subjects as much as possible. However, do so in a natural manner. Use the Caltech supplemental essays as a chance to supplement the quantitative parts of your application such as your grades and GPA with qualitative attributes of who you are as a student, person, and peer.


This Caltech essay guide on was written by Sarah Kaminski. Looking for more admissions support? Click here to schedule a free meeting with one of our Admissions Specialists. During your meeting, our team will discuss your profile and help you find targeted ways to increase your admissions odds at top schools. We’ll also answer any questions and discuss how CollegeAdvisor.com can support you in the college application process.