How to Answer the 2025-2026 Caltech Supplemental Essays

Deciding to go to the California Institute of Technology is the dawn of a new academic adventure! Caltech is a highly selective private research university with a 3% acceptance rate. With such a competitive application pool, your very best writing is required. 

In this guide, we’ll go over each prompt and help you break the Caltech essays down so you’ll know exactly what is being asked. Let’s get started!

The Caltech essays

Caltech’s supplemental essay prompts are a way for you to show the admission’s readers exactly who you are and why you should be part of the next undergraduate class. Even responding to the optional prompts shows Caltech that you want to be there and are willing to go the extra mile to prove that. 

Remember, applicants should emphasize STEM in their essays as much as possible since that’s one of the primary focuses of Caltech. So, keep reading below to learn more about Caltech supplemental essay prompts!

Essay #1: Your STEM Future – STEM Academic Interests

“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?

*Note that you are under no obligation to follow this choice if admitted.

Why did you choose your proposed area of interest? If you selected ‘other’, what topics are you interested in pursuing?” (Min: 100 / Max: 200 words)

Applicants should see this prompt as an opportunity to discuss their passions in STEM or any other Caltech program. However, it’s important to discuss more than just what your desired major is; be sure to talk about how Caltech plays a part in whatever interests you share. 

What’s so unique about this option (which is what majors are called at Caltech) that you can’t stop thinking about it? Is it daring? Are you the only one in your family to do it? Use this essay to show your drive and initiative. 

Questions to consider:

• Why do you want to study your major at Caltech?
• What is something unique about the majors that Caltech offers?
• What topics do you feel passionate about and why?

Essay #2: Your STEM Present – Curiosity

‘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)

This prompt is an exciting opportunity to do just as it says “nerd out”! While you might be especially passionate about your chosen area of interest, keep in mind that you have a pretty small word limit here. This essay allows the admissions committee to get a better sense of your personality and interests, so try and have some fun with it!

Essay #3 Your STEM Past: Prior Experiences

“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. Select one of the following two STEM experience prompts to respond to:”

Prompt #1

“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)

Caltech is clear in this prompt that your response should focus on some aspect of science, technology, engineering, and/or mathematics (STEM). While your experiences might seem similar to other applicants, try to set yourself apart by incorporating a personal aspect to your essay. 

Explain to the reader where your love of STEM started or grew during your time in high school and how that might contribute to your desire to attend Caltech. You could possibly even  talk about a STEM problem and how have or will solve it.

While the word count is short, applicants should also explain what they want to learn more about or explore further and why. Doing so further demonstrates your interest in Caltech if you’re able to make a connection between what you’re curious about and what you love about this specific university. 

Questions to consider:

• Who motivated you to get involved in STEM? Was it a mentor or a family member?
• How does CalTech fit into your pursuit toward a future in STEM?
• What are you most curious or excited about in STEM? 

Prompt #2

“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)

While this question is very similar to the prior one, there are some things that set it apart. For starters, this prompt specifically asks about a notable experience you’ve had in the STEM world. One way to think of it is the moment you realized you wanted a career or major in STEM.

Take the admissions office on a journey with this prompt, and tell them your story. You want them to feel the impact of this experience and how it was pivotal for you.

Questions to consider:

• If this experience hadn’t happened, where would you be?
• Why has this experience stayed with you?
• How does this experience relate to CalTech? Does it align with their core values or mission statement?

Essay #4: Creativity in Action

“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 how to 3D- print dorm decor to experimenting in the kitchen. How have you been a creator, inventor, or innovator in your own life?” (Min: 200 / Max: 250)

The definition of innovation is the introduction of something that’s never existed before. Remember, innovation and invention doesn’t have to be some large, spectacular creation. 

Your innovation can be something new you’ve added to your life or doing something that you’ve never heard of. Even being the first person in your family to go to college could be a form of innovation–you just have to get creative! 

Questions to consider:

• Are you the first person to do something in your family?
• Have you created something that you think is fresh or different?
• Do you consider yourself a trailblazer? Why?

Required Short Answer Questions

The following section requires students to choose two of the four prompt options to answer both questions in 250 words or less. That means you can either spend exactly 125 words per question or split it up however you like.

Short Answer Prompt Option #1:

“What is an interest or hobby you do for fun, and why does it bring you joy?”

When you answer this question, try and think about something specific or unique to set you apart from other applicants. Don’t just say, “I like to read books.” Talk about the specific kinds of books you like to read and why. Do you have a favorite book? If so, what makes that book special to you? There’s a reason that you run into this question so often when you first meet someone. It’s a lighthearted way to get to know someone’s interests.

Questions to consider:

• Why do you want to share this with the admissions office?
• What are some activities or pieces of media that bring you joy?
• What do you like to do outside of STEM and academics?

Also see: How to write an essay about yourself

Short Answer Prompt Option #2:

“If you could teach a class on any topic or concept, what would it be and why?”

To teach a class, you need to have somewhat of an expertise on the topics. Think about topics that you already have a good understanding of or expertise. Maybe you’re not ready to teach a class about it just yet, but what would you like to learn more about? This could also be a great topic for this essay. After all, many people believe the best way to learn is to teach.

Questions to consider:

• What topics are you already very knowledgeable in or interested in learning more about?
• What subjects would you feel confident in tutoring others in?
• Why do you think teaching helps us learn?

Short Answer Prompt Option #3:

“What is a core piece of your identity or being that shapes how you view and/or interact with the world?”

This is a great question to answer if you find that your identity is a big part of your sense of self and it’s something that you are comfortable sharing with others. You could talk about how your identity shapes how you interact with your community. Most college campuses want to encourage students to express their personal identity and perspective with their college community.

Questions to consider:

• How has your identity shaped your values and what you look for in a community?
• When you describe yourself, what comes to mind?
• What conditions help you feel more comfortable when interacting with the world?

Short Answer Prompt Option #4:

“What is a concept that blew your mind or baffled you when you first encountered it?”

For this question, start by writing down all of the things that first pop into your mind. We learn new things every day, so for something to stick with you, it probably has to be somewhat mind blowing. Remember to have fun with this one! If nothing comes to mind after some brainstorming, you could even look up some scientific discoveries or mathematical solutions. You might just find something new that is completely mind blowing!

Questions to consider:

• What are concepts that fascinate you?
• Where do you tend to learn about things that baffle you? Inside or outside of the classroom?
• What’s your favorite fun fact?

Optional Question

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

Extenuating circumstances, in this case, are any events or situations that make it difficult for you to complete coursework or produce your best grades. This might be your home life, unexpected personal events or other circumstances. Based on the prompt, it’s likely that extenuating circumstances are mentioned elsewhere, and if so, you don’t have to answer this question again.

Fortunately, this prompt doesn’t have a word count, which means you can open up as little or as much as you are comfortable with. Be sure to include background or context surrounding your circumstance, so that the admissions committee can truly understand what’s going on for you and how it impacts your education.

Questions to consider:

• Have you experienced any notable difficulties that have impacted your grades or class attendance?
• Are you comfortable sharing your extenuating circumstances with Caltech?

Final thoughts for applicants

As you wrap up your Caltech essays, it’s important to keep a couple of things in mind. One of the most important things is noticing word count for each prompt. A majority of the prompts are 100-200 words with only a few exceptions. This means it’s ideal to get to the main point of your essay as soon as possible. 

Potential Caltech students should also take time to read through each essay submission to check for errors or any issues with the flow and readability of your essays. It can be helpful to ask your teachers, peers, or family members to read over your submission and get feedback to improve on your writing and storytelling skills. 

The world wasn’t built in a day, so don’t overwhelm yourself! There are resources here to help as well if you’re struggling with brainstorming your essay topics. 

Additional resources

Since you’re considering pursuing higher education, it’s important to have all the resources you can get at your fingertips. Check out some of these Scholarships360 links to learn more!

• Learn how extracurriculars impact your application
• Find out about fully funding your education with scholarships
• Decide on when to submit your application to college

Remember to apply for all the scholarships you qualify for while you are eligible!