50+ Science Fair Project Ideas That Actually Work (By Subject) With Diagrams

Science Fair Project Ideas (Easy to Advanced) 50+ Topics With Materials (2026)

If you are looking for science fair project ideas that you can actually build and explain, start here. I have seen students waste days on vague ideas. My rule is simple. Pick something measurable, keep it safe, and keep it finishable.

Below you will find ideas by subject, plus a quick method to pick the right project based on your time and budget. I have also added two ready to use diagrams you can paste on a display board.

Scientific method (diagram)

How to pick a topic fast (my checklist)

1. Pick a measurable project. If you cannot plot a graph, scoring becomes harder.
2. Keep it safe. Avoid high voltage, pressure vessels, and unsafe chemicals.
3. Keep it finishable. Prototype in 2 days and improve over a week.
4. Choose one variable. Change only one thing and measure the effect clearly.

Science fair project ideas by subject

A) Physics projects (15 ideas)

1. Maglev train working model with stability comparison for different magnet layouts.
2. Periscope construction with mirror angle explanation and field of view measurement.
3. Laser diffraction measurement to estimate hair thickness.
4. Simple spectrometer using DVD grating to compare LED and CFL spectra.
5. Friction mapping of different surfaces using an inclined plane.
6. Heat sink comparison and temperature rise graphs for different fin shapes.
7. Solar panel IV curve and maximum power point experiment.
8. Wireless power transfer distance versus efficiency experiment.
9. Newton law of cooling curve fitting for different containers.
10. Vibration frequency versus length for a cantilever beam.
11. Eddy current braking demonstration and deceleration graphs.
12. RC circuit charging curve and time constant extraction.
13. Wind turbine blade angle versus power output mini study.
14. Optical fiber bending loss curve versus bend radius.
15. Sound absorption comparison of materials using phone microphone and frequency analysis.

B) Chemistry projects (12 ideas)

1. Effect of temperature on reaction rate using safe household reactions and time measurement.
2. Water filtration comparison using sand, charcoal, and cloth with turbidity scoring.
3. Corrosion study of metals in salt water, vinegar, and plain water over time.
4. pH indicator from natural sources and pH mapping of household liquids.
5. Crystallization project: crystal size versus cooling rate.
6. Soap making variables: hardness and foam versus oil type.
7. Electrolysis mini setup and gas volume versus time.
8. Solubility curve: salt or sugar solubility versus temperature.
9. Milk adulteration test survey using simple safe checks and data table.
10. Chromatography of inks using paper and solvents, separation distance comparison.
11. Biodegradable plastic from starch and mechanical strength comparison.
12. Hard water softening methods comparison and soap lather test scoring.

C) Biology projects (12 ideas)

1. Plant growth versus light color using LED colors and weekly height data.
2. Seed germination rate versus salt concentration.
3. Effect of fertilizer type on leaf count and growth.
4. Hand wash effectiveness test using safe agar plate demonstration or proxy method.
5. Effect of music or vibration on plant growth with controlled setup.
6. Natural insect repellent comparison and count of insects repelled.
7. Food spoilage study at different temperatures and time to spoil.
8. Water quality study: compare samples using basic test strips and clarity scoring.
9. Respiration rate in yeast under different sugar concentrations.
10. Photosynthesis bubble count in aquatic plants under different light intensities.
11. Ant colony observation and path preference experiment with safe food options.
12. Composting speed versus material mix and temperature trend.

D) Earth and environment projects (11 ideas)

1. Rainwater harvesting model with flow rate and storage calculation.
2. Solar cooker design comparison and heating time graphs.
3. Air quality mini study using public AQI data and local observations.
4. Noise pollution mapping by location and time using phone decibel meter trends.
5. Plastic waste audit at home or school with category charts.
6. Greywater filtration and reuse model with clarity comparison.
7. Soil moisture retention: compare soil types and water loss over time.
8. Effect of mulching on soil temperature and moisture retention.
9. Wind direction and speed logging and weekly wind rose chart.
10. Compost versus chemical fertilizer impact on plant growth with data table.
11. Insulation comparison for a box and temperature retention over time.

Two build diagrams you can paste on the display board

Maglev layout (simple)

Periscope ray path

Related posts

• Physics Project Ideas for Engineering Students
• Maglev Train Working Model
• Build a Periscope

If you tell me your grade level, budget, and time, I can shortlist the best 8 topics from this page and suggest the exact measurements and graphs for each.