Good science fair projects for high school students test one question and produce data you collect or analyze yourself. Below are 22 ideas: six you can run at home, then 16 grouped by field. Each lists the question, what you need, the level, the time and the data you'll end up with.
Projects with people, animals or microbes usually need approval before you start, and those ideas say so. If you'd rather build something than run an experiment, start with our STEM project ideas for high school students.
Which science fair projects can you do at home?
You can run projects on plant growth, water filtration, nitrate, sunscreen, de-icers and surface heat at home with store-bought materials. None involves people, animals or microbes, the areas where ISEF rules require approval before you start. Plan a control and at least three runs per condition.
1. LED color and seedling growth
- Question: Does red, blue or white LED light change how tall radish seedlings grow in 21 days?
- You need: radish seeds, potting soil, cups, three LED bulbs of equal wattage, a ruler and a kitchen scale
- Level and time: beginner; 4 weeks
- Data you get: daily height, leaf count and final dry mass for each light color
- Limit: equal wattage doesn't mean equal light, so keep every bulb the same distance from its cups and note this in your results
2. Layered water filters
- Question: Which order of gravel, sand and activated charcoal clears muddy water best?
- You need: cut plastic bottles, gravel, sand, activated charcoal, coffee filters and muddy water
- To measure cloudiness: a homemade turbidity tube, which is a clear tube with a marked disk at the bottom
- Level and time: beginner; 2 weeks
- Data you get: cloudiness before and after each design, plus flow rate in milliliters per minute
- Safety: don't drink the water; this test measures cloudiness, not germs
3. Nitrate and pitcher filters
- Question: Do pitcher or faucet filters remove nitrate from water?
- You need: nitrate test strips, two or three filter brands, distilled water and fertilizer with nitrate nitrogen on its label, to add a known amount
- Level and time: beginner; 2 weeks
- Data you get: nitrate readings before and after each filter, three trials each, compared with EPA's drinking water limit of 10 mg/L
- Units: EPA's limit is measured as nitrogen, so check which unit your test strips use
4. Sunscreen and UV light
- Question: How much more UV does SPF 50 block than SPF 15, and do mineral and chemical sunscreens differ?
- You need: UV-sensitive beads or a UV meter, clear sheet protectors, several sunscreens and sunlight
- Level and time: beginner; 2 weeks
- Data you get: UV readings or bead color scores under each sunscreen film
- Limit: this compares UV blocking through a thin film; it doesn't measure SPF on skin
5. De-icer speed
- Question: Which melts the most ice in 30 minutes inside a freezer: rock salt, calcium chloride, sugar or sand?
- You need: ice trays, the four de-icers, a freezer, a kitchen scale, gloves and safety goggles
- Level and time: beginner; 1 to 2 weeks
- Data you get: grams of meltwater per gram of de-icer every 10 minutes
- Safety: calcium chloride can irritate your eyes and gets hot as it dissolves. Read its Safety Data Sheet and fill out a risk assessment form with an adult before you start.
6. Surface heat on a sunny day
- Question: How much hotter than the air do asphalt, concrete, grass and shaded soil get on a sunny afternoon?
- You need: an infrared thermometer, an air thermometer and a spreadsheet
- Level and time: beginner; 3 to 4 weeks of readings
- Data you get: hourly surface temperatures for each material, with air temperature and cloud cover
What are good biology science fair projects for high school?
Yeast, bread mold, duckweed and bird counts make easy first biology projects because they need little equipment. ISEF exempts baker's yeast and bread mold studies from pre-review, though you still fill out a risk assessment form. Projects that grow bacteria need approval from your fair's Scientific Review Committee (SRC) and a lab.
For summer-length projects, see our summer biology projects for high school students.
7. Yeast and sugar type
- Question: Which sugar (glucose, sucrose or lactose) makes baker's yeast produce the most carbon dioxide?
- You need: baker's yeast, the three sugars, warm water, bottles, balloons and a measuring tape
- Level and time: beginner; 1 to 2 weeks
- Data you get: balloon circumference every 10 minutes for an hour, with five trials per sugar
8. Bread mold and natural preservatives
- Question: Do vinegar, cinnamon or salt delay mold on bread?
- You need: slices from one loaf, zip-top bags, the three treatments and a phone camera
- Level and time: beginner; 2 weeks
- Data you get: days until the first visible mold on each slice
- Rules: ISEF exempts this from pre-review only if each trial ends at the first sign of mold; throw each bag away sealed
9. Microplastics and duckweed
- Question: Do microplastic particles slow duckweed growth?
- You need: duckweed from an aquarium or pond supplier, cups, a grow light, a kitchen scale and polyethylene microbeads from a craft or science supplier
- Level and time: intermediate; 3 to 4 weeks
- Data you get: frond counts every two days and the growth rate at each concentration, in milligrams of beads per liter
- Safety: if you grind your own plastic, wear a dust mask, and never melt or burn plastic
10. Plant extracts against bacteria
- Question: Do garlic or tea tree extracts stop bacterial growth as well as a commercial antiseptic?
- You need: a school or university lab, a BSL-1 strain from a science supplier, agar plates, paper disks and a ruler
- Level and time: advanced; 6 to 8 weeks, plus approval time
- Data you get: the zone of inhibition, in millimeters, around each extract and the antiseptic
- Rules: you need SRC approval first, and BSL-1 work must happen in a BSL-1 or higher lab. Don't use swabs from household surfaces: adding disks means opening the dish, and an opened dish of unknown microbes counts as BSL-2 work.
11. Bird activity and weather
- Question: Does bird activity at a park change with temperature or time of day?
- You need: binoculars, a tally sheet and a thermometer or weather app
- Level and time: beginner; 4 to 6 weeks
- Data you get: birds counted per 15-minute watch, by time and temperature
- Rules: watching is exempt from pre-approval only with no interaction and no change to the habitat. Adding a feeder is a change, so get SRC approval first.
What are good physics and engineering science fair projects?
Good physics and engineering projects test a design with measurements: bridge trusses, sound-blocking materials, drag shapes and solar trackers. Most use craft supplies, a kitchen scale or an Arduino. Build at least three copies of each design, or run three trials per condition, so judges can see your results repeat.
For more build-and-test ideas, see our engineering projects for middle and high school students.
12. Bridge truss strength
- Question: Which truss design (Warren, Pratt or Howe) holds the most weight per gram?
- You need: craft sticks or balsa, wood glue, a bucket, sand and a scale
- Level and time: beginner; 2 to 3 weeks
- Data you get: load at failure, bridge mass and strength-to-weight ratio for three bridges per design
13. Sound-blocking materials
- Question: Which material (cork, recycled denim, foam or cardboard) blocks the most sound at the same thickness?
- You need: a shoebox, a speaker playing test tones, a sound meter app and samples cut to the same size
- Level and time: beginner; 2 weeks
- Data you get: the drop in decibels for each material at low, middle and high pitches
14. Drag in a homemade wind tunnel
- Question: Which nose shape (flat, rounded or pointed) has the least drag?
- You need: a box fan, cardboard, drinking straws to straighten the airflow, a kitchen scale and clay shapes of equal width
- Level and time: intermediate; 3 to 4 weeks
- Data you get: drag force for each shape at each fan speed, measured with the scale and a simple lever
15. Solar tracker against a fixed panel
- Question: How much more energy does a panel that follows the sun collect than a fixed one?
- You need: two identical small solar panels, an Arduino, a servo motor, two light sensors and a current sensor
- Level and time: intermediate; 4 to 6 weeks
- Data you get: watt-hours per day for each panel over at least two weeks, with weather notes
What are good computer science projects for a science fair?
A computer science project should test a model against a simple baseline and report where it fails. All three ideas below use public data. ISEF exempts publicly available datasets from IRB review when you have no contact with the people in them.
16. Medical image classifier
- Question: How much better than a simple baseline is a small neural network at spotting pneumonia on chest X-rays?
- You need: a laptop or free cloud notebook, Python and a public, labeled chest X-ray dataset
- Level and time: advanced; 6 to 10 weeks
- Data you get: accuracy, sensitivity, specificity and a confusion matrix for each model
17. Small and large models for plant disease
- Question: Can a model small enough for a phone match a large model at spotting leaf disease?
- You need: a laptop or free cloud notebook, Python and a public dataset of labeled leaf photos
- Level and time: advanced; 6 to 8 weeks
- Data you get: accuracy, model size and prediction time per image for each model
18. Hot days in your city since 1970
- Question: Has the number of days above 90°F in your city changed since 1970?
- You need: daily temperature records for your city from NOAA's free Climate Data Online, plus a spreadsheet or Python
- Level and time: intermediate; 3 to 4 weeks
- Data you get: a yearly count of hot days, a trend line and a statistical test of the trend
What are good psychology and behavioral science fair projects?
Each psychology idea here tests one habit, such as study method, phone alerts, music or sleep, against a measurable score. Every one involves people, so you need IRB approval before recruiting anyone, and surveys count. Participants under 18 need their own agreement plus a parent's written permission.
Approval deadlines come early: Los Angeles County's is November 2, 2026, for a fair in March 2027.
19. Spaced practice against cramming
- Question: Do students remember more vocabulary a week later after spaced practice than after one long session?
- You need: volunteer classmates, 30 words in a language they don't know, a quiz and signed permission forms
- Level and time: intermediate; 4 to 6 weeks plus IRB review
- Data you get: quiz scores for each group one day and one week later
20. Phone notifications and attention
- Question: Do phone notifications lower scores on a timed attention task?
- You need: volunteers, a free online attention test, phones set to silent or to notify, and permission forms
- Level and time: intermediate; 4 to 6 weeks plus IRB review
- Data you get: accuracy and reaction times with and without notifications
21. Music and reading scores
- Question: Does music with lyrics lower reading comprehension more than instrumental music?
- You need: volunteers, headphones, three passages of similar difficulty with quizzes, and permission forms
- Level and time: intermediate; 3 to 5 weeks plus IRB review
- Data you get: quiz scores in silence, with instrumental music and with lyrics
22. Sleep and working memory
- Question: Do teens who sleep less score lower on a working memory test?
- You need: volunteers, a two-week sleep diary and a digit-span memory test
- Level and time: intermediate; 4 to 6 weeks plus IRB review
- Data you get: average nightly sleep and digit-span scores, plus the correlation between them
How do you pick and scope a science fair project?
Pick a field you'd read about for fun, then narrow it to one thing you change and one thing you measure. Check whether it needs approval and whether you can finish it before your fair. ISEF judges score whether your results repeat and whether you collected enough data to support your conclusions.
- Narrow the question. "Does light affect plants?" becomes "Does red, blue or white LED light change radish height after 21 days?"
- Check the rules. If people, vertebrate animals or microbes are involved, find your fair's pre-approval deadline first.
- Plan a control and repeats. Decide what stays the same, and run each condition at least three times.
- Write the research plan before you start. ISEF requires one, covering your question, procedures, risks, data analysis and sources.
- Keep a dated data book. ISEF calls a data book and a research paper "strongly recommended" for judging.
- Leave time for analysis. Finish experiments two to three weeks before your fair so you can graph, run statistics and make your poster.
In our Nova Research Program, you design and complete original research one-on-one with a mentor.
Which science fair projects need approval before you start?
Under ISEF rules, projects with human participants, vertebrate animals or potentially hazardous biological agents, such as bacteria, need approval before you start. A school IRB or your fair's SRC does the review. Surveys count as research with people, and running one without IRB approval is a listed reason projects fail to qualify.
- People: an IRB must approve the project before you recruit anyone, and minors need written parental permission. Exempt: testing your own invention alone if it's safe, public datasets, and watching public behavior without interacting or recording anything that identifies people.
- Vertebrate animals: SRC approval comes first, unless you only observe with no interaction and no change to the animals' environment.
- Microbes: SRC approval and a BSL-1 or higher lab; never culture them at home. Baker's yeast fermentation and mold on food, stopped at the first sign of mold, are exempt from pre-review but need a risk assessment form.
- Chemicals: ISEF doesn't require pre-approval, but you must read each Safety Data Sheet and do a risk assessment with an adult supervisor first. Some fairs, including Los Angeles County's, require pre-approval for hazardous chemicals too.
Read our guide to getting IRB approval before you write consent forms. Then check your plan against Society for Science's list of reasons projects fail to qualify.
Rules checked October 2026 against Society for Science's 2026-27 ISEF rules.
Frequently asked questions
How long does a science fair project take?
The ideas above take 1 to 10 weeks of experiments, plus time for planning, approval and analysis. ISEF caps a project at 12 months of continuous research. Check 2026-27 fair dates in our guide to science fairs and competitions for high school students and work backward.
What makes a science fair project win?
ISEF's judging criteria score the research question (10 points), design and methodology (15), execution (20), creativity and impact (20) and presentation (35). The interview alone is worth 25 points, and judges look at how independently you worked and whether you understand your results' limits. A project that skipped required pre-approval fails to qualify, whatever its score.
Can you use AI tools in a science fair project?
Yes, as a resource you cite. ISEF rules don't allow generative AI to write your research plan, abstract, poster or citations.
Is a science fair project the same as a research project?
Nearly. Both test a question with data you collect or analyze, but a fair project ends in a poster and a judge interview. ISEF still strongly recommends writing a research paper as well.
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