100+ Science fair project ideas 2026

Finding a project that is interesting, manageable, and fair-ready can take longer than the experiment itself. These science fair project ideas for 2026 give U.S. high school students more than 100 practical starting points, from classroom tests to data-based investigations.

A strong project asks one focused question, changes one main variable, and measures results consistently. Check your teacher’s safety rules before ordering materials, especially for work involving chemicals, devices, people, animals, or biological materials.

How to choose the right science fair project

Start with a topic you would still want to work on after the first trial fails. A question from your home, school, hobby, or future career is easier to explain than a copied experiment. Keep the design narrow enough to repeat and finish on time.

Choose a question you can measure with numbers, ratings, counts, or timed observations. Change one independent variable, keep other conditions consistent, and complete at least three trials per condition. Record results as you go and avoid restricted procedures or unapproved testing on people and animals.

Match the project to your time and resources. A short experiment can still be impressive when the method is fair and the data is clear.

Project factor	Best choice for a short deadline	Best choice for a longer deadline
Data collection	Timed trials, direct comparisons, and simple measurements	Plant growth, weather tracking, and repeated prototype tests
Materials	Household or classroom supplies	Sensors, kits, or borrowed equipment
Analysis	Averages, bar graphs, and basic comparisons	Trend lines, multiple trials, and design revisions
Risk level	Low-risk observations and supervised experiments	Projects that need advance approval or safety planning

Organize your proposal, research log, display board, and presentation early. Students who need planning support can use do my project for structure and revision.

High school science fair projects, organized by grade

Difficulty depends on experience, not only grade level. Freshmen can begin with controlled experiments, while upperclassmen may add engineering, public data, and local research questions. Each grade section below has 11 ideas, giving you 44 project options organized by difficulty.

9th grade

Ninth-grade projects work best when the setup is visible and the results can be collected in a few days. These options use accessible materials and leave enough time for repeat trials.

1. Test how water temperature affects the time needed for sugar to dissolve.
2. Compare paper airplane designs by average flight distance.
3. Measure how ramp angle changes a toy car’s travel time.
4. Test whether soil type affects bean seed germination.
5. Compare insulation materials by how quickly warm water cools.
6. Investigate how salt concentration changes the freezing time of water.
7. Test which natural material filters visibly cloudy water most effectively.
8. Measure how light distance affects solar calculator performance.
9. Compare marker ink separation using paper chromatography.
10. Test how paper spinner blade length affects falling time.
11. Measure how magnet distance changes the number of paper clips lifted.

10th grade

Sophomore projects can use more detailed measurements and clearer control variables. Repeat trials, make a graph, and note factors that may have influenced the final results.

1. Compare the sound absorption of fabric, foam, cardboard, and cork.
2. Test how pH affects the rusting rate of steel wool.
3. Investigate whether mulch type affects soil moisture retention.
4. Compare small wind turbine blade shapes by electrical output.
5. Test how screen brightness changes battery-drain rate on one device.
6. Measure how pendulum length changes swing period.
7. Test whether different colors absorb heat at different rates.
8. Compare the friction of sandpaper grades using the same sliding block.
9. Test how water salinity changes electrical conductivity.
10. Measure how different container shapes affect water evaporation.
11. Investigate whether storage temperature affects apple browning.

11th grade

Junior-year projects can use stronger controls, larger data sets, or a local issue. Narrow a school or neighborhood question to one measurable variable, then state the limits of the method honestly.

1. Analyze whether LED light wavelengths affect basil growth.
2. Test how temperature changes the output of a small solar panel.
3. Compare homemade water filters using turbidity measurements.
4. Investigate the strength-to-weight ratio of model bridge designs.
5. Compare compost mixtures by temperature change over several weeks.
6. Build and test a moisture-alert system for houseplants.
7. Compare passive cooling materials for a small model structure.
8. Test how biochar amounts affect water retention in soil.
9. Compare solar oven designs by the highest internal temperature reached.
10. Investigate whether leaf shape affects the rate of water loss.
11. Test whether acoustic panel spacing changes recorded sound reduction.

12th grade

Senior projects can be more original, but complete data matters more than a large unfinished idea. Add an engineering revision, public dataset, or local setting where useful, and check approval rules before specialized work.

1. Model local heat-island patterns with public weather data and field observations.
2. Compare low-cost sensor accuracy against a classroom reference instrument.
3. Test how biochar particle size affects soil-water retention.
4. Build an algorithm that classifies approved recyclable-item images.
5. Optimize a small hydroponic setup by changing nutrient concentration.
6. Compare biodegradable packaging materials by strength and water resistance.
7. Test passive cooling designs for a model structure under a lamp.
8. Create a low-cost device that tracks indoor air conditions.
9. Analyze whether tree-canopy coverage predicts surface temperature on campus.
10. Compare filtration media for removing particles from simulated stormwater.
11. Model how green-roof depth affects runoff from a small roof system.

High school science fair project ideas, organized by subject

Subject-based browsing helps when you know what questions you enjoy. Biology rewards patient observation, while physical science favors controlled measurements. The five subject sections below provide another 55 ideas, separated by the type of research and evidence they require.

Life science

Life science projects should stay safe and practical. Seed germination, plant growth, compost, noninvasive observations, and yeast activity can produce reliable results without complicated approvals.

1. Test how light color affects lettuce seedling height.
2. Compare seed germination in sand, potting soil, and coconut coir.
3. Investigate whether leaf surface affects water loss.
4. Test how different sugar types affect yeast carbon dioxide production.
5. Compare the effect of watering schedules on herb growth.
6. Measure how salinity changes radish seed germination.
7. Study which bird-feeder placement attracts the greatest variety of birds.
8. Compare natural preservatives for slowing apple browning.
9. Test whether seed size predicts germination speed within one plant species.
10. Investigate how compost tea dilution affects plant growth.
11. Compare shade-cloth levels by soil temperature and plant height.

Earth science

Earth science works well with local data, weather records, maps, and physical models. Keep location, time, method, and equipment consistent when collecting outdoor measurements.

1. Compare erosion rates in model soils with different ground covers.
2. Test how slope angle changes water runoff in a tray model.
3. Track cloud types and compare them with local precipitation records.
4. Compare rock samples by density and water absorption.
5. Model how vegetation changes stormwater flow.
6. Test how sand particle size affects drainage rate.
7. Compare the heat absorption of light and dark roofing materials.
8. Analyze monthly air-quality trends using public local data.
9. Model earthquake-resistant structures using identical building materials.
10. Test how different land surfaces affect evaporation rate.
11. Investigate how moisture changes the compressive strength of model soil.

Physical science

Physical science covers motion, force, electricity, heat, light, sound, and energy. Choose one measurable outcome, such as speed, voltage, temperature, distance, or sound level, and keep the setup consistent.

1. Compare the conductivity of common metal and nonmetal materials.
2. Measure how temperature affects a rubber band’s stretch.
3. Test how blade angle affects a mini wind turbine’s output.
4. Compare the reflectivity of different surface finishes.
5. Investigate how marble mass changes travel speed on a ramp.
6. Test which material blocks sound most effectively at a fixed distance.
7. Compare magnet strength through different barrier materials.
8. Measure how water depth affects the speed of a floating object.
9. Test how wheel diameter changes a rubber-band car’s distance.
10. Compare paper wing shapes by lift or glide time.
11. Investigate how wire length affects electrical resistance in a supervised setup.

Chemistry

Chemistry projects require supervision, labeled materials, and safe cleanup. Track a visible property such as pH, reaction time, color, mass, temperature, or conductivity.

1. Compare the pH of common beverages before and after dilution.
2. Test how temperature affects crystal growth from a safe saturated solution.
3. Investigate how concentration changes the reaction time of effervescent tablets.
4. Compare natural indicators made from red cabbage, berries, and turmeric.
5. Test how different acids affect eggshell mass over time.
6. Compare approved household cleaners on a standard stain.
7. Investigate how water hardness affects soap lather.
8. Test how salt concentration changes water conductivity.
9. Compare storage conditions for changes in juice vitamin C test results.
10. Measure how particle size changes the dissolving rate of a safe solid.
11. Compare the corrosion of identical metal samples in safe household liquids.

Environmental science

Environmental science becomes easier to manage when you connect a broad concern to one observable system. Waste audits, water models, packaging tests, energy comparisons, and local outdoor measurements can all provide clear evidence.

1. Compare reusable and disposable packaging by weekly waste mass.
2. Test which natural mulch reduces water loss from soil.
3. Measure how different materials remove visible particles from model runoff.
4. Compare the energy use of common light bulbs under identical conditions.
5. Estimate how refillable bottles reduce single-use plastic in a class sample.
6. Compare how quickly compostable materials break down in controlled soil.
7. Test how pavement and grass affect rainwater infiltration.
8. Compare recycled paper, fabric, and foam as insulation materials.
9. Conduct an approved audit of recycling contamination at school.
10. Compare water use in different hand-washing methods with a timed flow test.
11. Build a model green roof and compare its runoff with a bare roof model.

Easy science fair project ideas

Easy projects are not weak projects. They work well for short deadlines, limited materials, and students who are completing their first formal experiment. Keep the question specific, repeat the test, and present the data in a simple graph.

1. Compare how quickly ice melts in different locations.
2. Measure which type of ball bounces highest on the same surface.
3. Compare the strength of bridge shapes made from index cards.
4. Test how ramp height changes the speed of a toy vehicle.
5. Investigate which material keeps an ice cube frozen longest.
6. Compare how quickly different paper types absorb colored water.
7. Test whether cup shape changes the cooling rate of warm water.
8. Measure how different liquids affect the buoyancy of an egg.
9. Compare the flight time of parachutes made from different materials.
10. Test which homemade container best protects an egg from a short drop.
11. Investigate whether the amount of detergent changes bubble lifespan.

A simple idea still needs a complete presentation. Include your question, hypothesis, variables, procedure, results, graph, conclusion, and what you would change next time. For planning and formatting support, explore write my paper for me and use any help responsibly.

Frequently asked questions

How many trials should a science fair project include?

Three trials per condition are a practical minimum for many school projects. More trials can make results more reliable, especially when measurements vary.

Can a science fair project be an engineering design?

Yes. An engineering project identifies a problem, builds a prototype, tests it against criteria, and improves it through revisions. Use the engineering design process rather than forcing it into a traditional hypothesis format.

What makes a science fair project stand out?

Clear data, a fair test, honest limitations, and a readable display board matter more than a complicated topic. A focused project with repeatable methods often looks stronger than a broad experiment with scattered evidence.

Can I use a project idea from a website?

Yes, but make it your own by changing a variable, using a local setting, improving the method, or asking a more specific question. Credit sources and follow your teacher’s rules.

What should I avoid for a high school science fair?

Avoid unsafe experiments, testing people or animals without approval, culturing unknown microbes, and projects you cannot finish in time. Review school rules before ordering supplies.