20 Science Fair Ideas for Elementary Kids

By Emily Chen · October 10, 2026

What Makes a Good Science Fair Project

A strong project starts with a question, forms a hypothesis, tests it with an experiment, and draws conclusions. The process matters more than complexity.

Life Science Projects

1. Plant Growth and Light

Grow identical plants in different light conditions. Measure height weekly. Which grows tallest?

2. Seed Germination Variables

Test temperature, moisture, or light on seed sprouting. Count sprouted seeds daily.

3. Decomposition Race

Bury different materials (paper, plastic, fruit). Check monthly. What decomposes fastest?

4. Bird Feeder Preferences

Offer different seeds at identical feeders. Count bird visits by type. Which seed is preferred?

Physical Science Projects

5. Paper Airplane Distance

Build different designs. Measure flight distance. Which shape flies farthest?

6. Magnet Strength Test

Test how many paperclips different magnets hold. Does size predict strength?

7. Insulation Challenge

Wrap ice in different materials. Time melting. What keeps ice frozen longest?

8. Sound Through Materials

Tap a tuning fork against different surfaces. Rate sound transmission. Which conducts best?

Earth Science Projects

9. Soil Water Absorption

Pour measured water through sand, clay, potting soil. Collect and compare drainage.

10. Erosion Prevention

Build soil slopes with different covers. Simulate rain and measure soil loss.

Chemistry Projects

11. Crystal Growing Race

Compare crystal growth in sugar, salt, and borax solutions. Which forms largest crystals?

12. Cleaning Power Test

Test vinegar, baking soda, soap on identical stains. Rate cleaning effectiveness.

13. Rust Prevention

Treat nails with paint, oil, or nothing. Observe rust over weeks. What prevents rust?

Engineering Projects

14. Bridge Strength

Build bridges from straws, paper, or popsicle sticks. Add weight until collapse.

15. Egg Drop Challenge

Design containers to protect eggs from a fall. Test from increasing heights.

16. Solar Oven Design

Build ovens from boxes and foil. Melt cheese or chocolate. Compare designs.

Math and Technology

17. Dice Probability

Roll dice 100 times. Record results. Do actual outcomes match mathematical probability?

18. Password Strength

Test how long different password types take to crack using online checkers.

19. Color and Memory

Show word lists in different colors. Test recall accuracy. Does color affect memory?

20. Reaction Time Variables

Measure reaction time with ruler drop test. Compare by age, handedness, time of day.