On their website, Caltech begins by providing students the following directions:
“Fall 2026 Supplemental Application Essays
When you apply to Caltech through the Common App or QuestBridge Application, you will also submit the Caltech Specific Questions (for QuestBridge applicants, these questions come if you become a Match Finalist and you ranked Caltech). These questions change annually, are updated, and published in the summer.
The essays are an opportunity to tell us about yourself in your unique voice. There are no right or wrong answers but we do have some advice:
- Remember, Caltech is an unapologetic STEM institution. Literally, there is no way to write about too much STEM in your supplemental questions. So lean all the way in on the STEMiest of STEMmy topics (yep, those are made-up words but totally appropriate). Review our What We Look For page before you get started.
- Faculty at Caltech review files of the most competitive applicants. So don’t worry that your science won’t make sense to a lay-person because our faculty with PhDs conducting research that will change the world will understand what you’re saying. We promise.
- If there is anything important about who you are, what you’ve done, or how you’ve experienced your life – we want to know about it. Holistic review means whole person review. We’re here for whatever you want to share.
All Fall 2026 applicants will be asked to review Caltech’s guidelines on the ethical use of AI before submitting their supplemental essays.”
Be sure to review every single resource hyperlinked above before you begin drafting your essays. This will allow you to develop an understanding of Caltech’s values and what they hope to gain from reviewing your application.
Prompt 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.
Explanation:
While your indicated choice in major is not binding, it is a good way for you to establish your guiding passion for the admissions committee. Ideally, your first and second choice majors align with the academic endeavors and activities you have pursued and listed on your activities list. For example, if you completed a mechanical engineering internship and took an online course on the subject matter, your proposed area of interest should be mechanical engineering! Your second proposed area of interest can be closely related to your first area, or it can be a complementary interest related to your other endeavors, like Business, Economics and Management or Economics.
Why did you choose your proposed area of interest? If you selected ‘other’, what topics are you interested in pursuing?* (Min: 1 / Max: 200 words)
Explanation:
This prompt invites you to share the reason behind your interest in your intended academic field. Your response doesn’t need to be particularly groundbreaking, but it should be truly authentic. Is there a project from high school that developed your interest in this subject? A book that ignited your curiosity in this area? A summer program that introduced you to this field of study? Draw on some unique experience to show rather than tell your reader how you arrived at this interest. A word to highlight in this prompt is “excite.” Don’t hold back on expressing your intellectual curiosity and enthusiasm!
Sample:
I want to be a fortune teller.
No, I don’t need a crystal ball; my computer will suffice. My fascination with forecasting impending events has made me fall in love with economics and quantitative analysis.
In high school, I worked with my economics teacher to develop an independent study in econometrics where I attempt to predict the unpredictable. While my project is specifically about discovering the determinants of success in the Major League Baseball playoffs, what it really seeks to understand is how to better measure labor performance—in this case, that of professional athletes—which may be overlooked. Sports, specifically baseball, are a terrific sampling ground for labor analysis and prejudice regarding labor. In baseball, scouts historically value simplistic factors like players’ win-loss records or 40-yard dash times; however, the “Moneyball revolution” helped teams to discover that there are players who struggle in traditional aspects of evaluation but possess undetected, often incredible, traits with their own inherent value. At Caltech, through courses like “Introduction to Sports Science,” I hope to develop the analytical capabilities and data-driven approaches that would allow me to eschew orthodoxy in favor of identifying the “diamonds in the rough.”
Prompt 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 words)
Explanation:
Just like in the previous prompt, Caltech wants to know what excites and stimulates you intellectually. Because of how similar this prompt is to the first one, make sure to use this space to reveal something new or to show a different side of you to the admissions committee. Is there a niche topic you’re obsessed with? Is there a problem or question you have spent days wondering about? What subject could you talk about for hours? This prompt is intentionally broad and gives the opportunity for eccentricities and personalities to shine! Once again, do not hold back on enthusiasm. Caltech should read your response and be able to tell how passionately you care about a certain topic, subject, or other intellectual pursuit. A successful essay would likely also demonstrate how you’ve interacted with this interest in your own life and how you might continue to do so on campus at Caltech.
Sample:
Upon waking, I immediately roll over and grab my pen and notepad from my nightstand and begin scribbling, my eyes barely open. Ever since I was little, I have been obsessed with decoding dreams and uncovering the messages behind their vivid imagery. Learning about lucid dreaming and REM sleep fuels my curiosity about the mind, and stacks of “Dream Dictionaries” frequently litter my nightstand.
As I’ve grown up, this obsession has flowed into other areas of neurobiology and psychology, from memory retention to goal-setting. I initiated “Thriving Tools” at my high school, an educational series aimed at empowering fellow students with science-backed strategies for improving memory, motivation, and effective learning. Friends’ successes—better sleep, information retention, and increased classroom confidence—were the ultimate reward.
At Caltech, I hope to further my scientific understanding of biology and to then utilize this information to create a community where people feel healthier and more empowered.
Prompt 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:
Tell us how you initially found your interest and passion for science or for a particular STEM topic, and how you have pursued or developed your interest or passion over the last few years. (Min: 100 / Max: 200 words)
Explanation:
Note that this prompt is two-pronged—it first asks you to describe what inspired your STEM-related interests, then they ways you have actively pursued those interests. The first half allows you to narrativize your beginnings in the STEM field, and as such, consider beginning with an engaging story to illustrate your burgeoning interest. The next thing that admissions officers want to see is a demonstration of initiative. Admissions officers want to not only read about how you first dipped your toe in this topic or passion, but how you then went above and beyond in pursuing this passion. How did you explore it beyond the classroom? How has this passion grown and what has it culminated in? The more specific you can be in your writing, the better. Finally, how will you continue to develop this passion and show initiative on Caltech’s campus?
Sample:
Crouching in the corner of my mom’s office, I lifted the lid of the Tupperware container, eager to see what awaited. A gigantic smile spread across my face as I saw the treasure beneath: oozing strawberries covered with a fuzzy layer of white mold!
While this may sound like many people’s worst nightmare—my mother included—this moment was pivotal in my development as a scientist. I was in fifth grade when I became troubled by how strawberries in our fridge grew moldy in a matter of days. Determined to find the storage method that ensured the longest freshness, I placed strawberries in four different types of containers and tracked the mold growth.
Seven years later, not much has changed—just replace the Tupperware with Petri dishes and the moldy strawberries with incubated bacterial colonies. My internship with a local clinical laboratory has only deepened my passion for microbiology. Hands-on experiences like plating Petri dishes, culturing bacterial strains, and counting colonies probe me to ask even more questions. I am proud that my fifth grade strawberry experiment was just the first of many, and I hope to take advantage of Caltech’s extensive research opportunities to continue exploring my beloved biology.
Tell us about a meaningful STEM-related experience from the last few years and share how and why it inspired your curiosity. (Min: 100 / Max: 200 words)
Explanation:
This prompt is fairly straightforward in that it requires you to share some sort of anecdote related to a STEM experience. Make sure you are not just telling the story, but showing it through visual language and storytelling. The important thing to keep in mind is 1) to connect this to yourself and how this experience nurtured you as a curious intellectual and 2) to express how this experience aligns with Caltech or an opportunity you hope to pursue at Caltech.
Sample:
Intergenerational friendships are some of the most rewarding relationships. I should know; some of my dearest friends are over a thousand years old.
Last summer, I conducted environmental research focused on forest management across California redwood forests. Through this experience, I was able to bear witness to the great beauty that lies in these ancient, towering trees. Beyond their beauty, though, I was taken aback by how much there was to learn from them. My curiosity was sparked throughout my time as a researcher as I learned more about redwoods, from their remarkably high bark moisture content that makes them fire-resistant to their incredible carbon sequestration abilities. This experience taught me that, in a society where humans are often prioritized over other living things, it is essential to raise awareness for the well-being of plants and animals, including the underlying wisdom they provide. Through Caltech’s Environmental Science and Engineering program, specifically exciting classes like “Forest Ecology” and “Climate Science,” I hope to continue pursuing this curiosity about the natural world and to equip myself with the skills necessary to create solutions to environmental challenges that keep the needs of both humans and plants in mind.
Prompt 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 words)
Explanation:
This question is prompting you to highlight a time when you have thought out of the box or brought a unique idea to completion. Given that creativity is the focus of this prompt, consider how you might incorporate other disciplines into your answer, get creative with your storytelling, or select an off-the-wall anecdote to highlight your innovation. The idea of being a creator or inventor also implies a sense of initiative, grit, and leadership, so think about how you can showcase those qualities with your answer. Finally, end the essay by connecting this anecdote with how it informs the type of student or person you will be at Caltech and the impact you hope to make on the community there.
Sample:
“We’ve got a breach!” the special forces leader shouts, turning on the alarm and triggering signals throughout the museum. Flashing red lights illuminate the scene. Despite the villain’s success in sneaking over the fence, his plan is ultimately foiled.
While many would recognize this as a gripping action scene, few might connect it with the body’s immune response. Yet, during an AP Biology lecture on infection, I noticed striking parallels between our reactions to pathogens and the riveting scenes of my favorite movies. The vivid imagery of pathogens as villains and components of our immune system as various layers of defenses took my understanding of these processes to a new level.
Inspired, I combined my passions for biology and writing to create a play that translated scientific concepts into compelling narratives. After presenting it in class, I noticed that my framing of the immune response as a story helped my classmates not only engage with the material on a deeper level, but also retain information more effectively.
Encouraged by this feedback, I took my play to middle schools, hoping to bridge science and arts at an earlier age. I volunteered weekly to rehearse scenes and discuss their connections to immunology. Experiencing students’ overwhelming enthusiasm proved to me the value of combining two seemingly-opposed areas like science and art.
Caltech’s focus on interdisciplinary approaches aligns perfectly with who I am as a student and creator. At Caltech, I will continue integrating my passions and inspiring others to see the interconnectedness of disparate fields.
Required Short Essay Questions
Now it’s time for a little fun! Choose two of the four questions below and answer both in 250 words or less.
It’s up to you how you use your 250 words, whether that means you use exactly 125 words for each answer or you tell us about a niche interest in 30 words so you can spend 200 telling us about a core piece of your identity.
There is no ‘right’ way to choose which question to answer. If you’re all STEMmed out, feel free to tell us about a creative hobby. Or if you just can’t get enough math, tell us about a concept you can barely wrap your head around. Just remember the Caltech Honor Code and stick to 250 words for both answers combined.
KEY TIP
While you can certainly aim to write two essays of 125 words in length, we recommend taking a much more fluid approach when answering these questions. Begin by earnestly responding to the two prompts of your choice. Do not limit yourself as you freewrite. It will be in the editing process that you consider which answer can be provided in shorter form than the other, and this will only become clear through the iterative writing and editing process.
What is an interest or hobby you do for fun, and why does it bring you joy?
Explanation:
This prompt is the perfect place to be playful—no interest or hobby is too big or too small! This is an opportunity to step away from writing about pure academics, and it is a great way to humanize yourself and show Caltech the nuances that make up who you are. Write about something that you haven’t talked about yet in your application, and express why this interest or hobby is so meaningful to you.
If you could teach a class on any topic or concept, what would it be and why?
Explanation:
While this is a fun question that may initially seem random, it’s a great opportunity to tell the admissions committee about something you have a great deal of interest in or knowledge about, even if unrelated to your primary academic interests. For example, perhaps you have a dying passion for a particular artist, musician, performer, actor, or otherwise. You might want to teach a class solely about this particular individual and focus your curriculum on their artistry, impact, or philosophy!
What is a core piece of your identity or being that shapes how you view and/or interact with the world?
Explanation:
Almost all of the prompts thus far have been directly related to your interest in STEM, so if you choose to answer this prompt, consider it as an opportunity to show off a side of yourself or a part of your identity that you haven’t been able to yet! This could be a community that has shaped you, a hobby not yet talked about, or a culture you are a part of. The prompt is very open, so it would be a good idea to use a short anecdote (remember, maximum 150 words!) to structure the flow of your essay. Make sure to connect this anecdote to how it has impacted you as a person (i.e. how you see the world, how you treat others, how you approach challenges, etc.).
What is a concept that blew your mind or baffled you when you first encountered it?
Explanation:
In asking this prompt, Caltech is asking you to share a time when a discovery left you in awe. You might want to write about something like a historical concept, a certain postulate or theory, or a historical event you studied in school. No matter what you choose to write about, what’s important is that you use it as a tool to demonstrate your intellectual curiosity and character! Are you someone who seeks out challenging ideas? Do you like being forced to question your own assumptions? Begin by describing the shock upon encounter, describe why it shocked you, and how it changed your thinking or perspective. Be sure to demonstrate intellectual resilience and curiosity when faced with challenging or novel ideas.
Optional Academic Short Answer Questions (Found under the “Academics” tab of the Common App)
OPTIONAL: 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.
Explanation:
This is your chance to explain any difficulties or gaps in your application. Does your school only offer 2 AP classes and that’s why you didn’t have more on your transcript? Did you go through a hardship during high school that took away your focus or time from schoolwork? Did you have a younger sibling you were responsible for taking care of after school, which limited your ability to pursue certain opportunities? A good tip is to highlight instances where you were able to recover despite these challenges or show growth after these hardships.