Science fairs are a great way for students to explore questions they’re curious about, practice the scientific method, and present results in a clear, creative way.
This article gives you 50 science fair project ideas tailored for students — from simple experiments you can do at home to more advanced projects suitable for high school.
The first 30 projects are explained in detail with purpose, materials, step-by-step procedures, variables, expected results, safety notes, and tips for presentation. The last 20 ideas are shorter prompts you can use or expand into full projects.
Use these ideas as a starting point: adjust materials to what you have, pick a question that excites you, and make sure your project is safe and ethical. Each detailed project is written for students — clear, practical, and easy to turn into a science-fair display.
Must Read: Science Project Ideas — 150 Easy, Practical & Ready-to-Use Projects for Students
How to Choose and Plan a Science Fair Project
- Pick a question you care about. You’ll enjoy the project more and put in better work.
- Make it testable. Your question should allow experiments and measurable results.
- Keep it safe and realistic. Choose materials and procedures that are safe and fit your time and budget.
- Use the scientific method. State a hypothesis, test it with controlled experiments, collect data, analyze results, and draw conclusions.
- Document everything. Keep a lab notebook with dates, measurements, photos, and observations.
- Plan the display. Think ahead about graphs, photos, and a clear explanation of your findings.
30 Science Fair Project Ideas
Below each project you’ll find: Grade level suggestion, Aim, Materials, Procedure (brief steps), Variables, Expected results, Safety & presentation tips.
1. Does Plant Growth Differ under Different Colors of Light?
Grade level: Middle to high school
Aim: Test how different light colors affect plant growth.
Materials: Fast-growing seeds (radish or lettuce), identical pots, potting soil, LED bulbs or colored cellophane (red, blue, green, white/control), ruler, water.
Procedure: Plant seeds in identical pots. Place each pot under a different colored light (or cover with colored cellophane) but give equal light duration and water. Measure plant height and leaf number every 2–3 days for 2–3 weeks.
Variables:
- Independent: Light color.
- Dependent: Plant height, leaf count.
- Controlled: Seed type, soil, water volume, temperature, light duration.
Expected results: Blue or white light often promotes compact growth and leaf development; red may encourage stem elongation.
Safety & presentation tips: Use safe household lights. Show photos across days and a graph of growth over time.
2. How Does Temperature Affect the Rate of a Chemical Reaction (Baking Soda + Vinegar)?
Grade level: Elementary to middle school
Aim: Measure how reaction speed changes with temperature.
Materials: Baking soda, vinegar, measuring spoons/cups, thermometer, stopwatch, water bath (ice and hot water), balloons or gas collection setup.
Procedure: Place equal amounts of baking soda and vinegar in a container at different temperatures (cold, room, warm). Measure time to inflate a balloon or the amount of gas produced in a set time.
Variables:
- Independent: Temperature.
- Dependent: Rate of gas production (balloon size/time).
- Controlled: Amounts of reactants and container size.
Expected results: Reaction should be faster at higher temperatures.
Safety & presentation tips: Wear safety glasses; dispose safely. Use a table showing temperature vs. balloon circumference.
3. Which Type of Water Produces Healthier Plants — Tap, Distilled, or Rainwater?
Grade level: Middle school
Aim: Compare plant growth using different water sources.
Materials: Identical plants, pots, tap water, distilled water, collected rainwater, ruler, soil.
Procedure: Water identical plants with different water types while keeping all other conditions the same. Measure growth, leaf color, and health over several weeks.
Variables:
- Independent: Water type.
- Dependent: Plant growth metrics.
- Controlled: Light, soil, pot size, plant type.
Expected results: Some minerals in tap or rainwater may promote growth; distilled may lead to slower growth.
Safety & presentation tips: Label bottles and log pH of each water source if possible. Present a color photo comparison.
4. How Do Different Surfaces Affect the Speed of a Toy Car?
Grade level: Elementary to middle school
Aim: Investigate friction by measuring car speed on different surfaces.
Materials: Toy car, stopwatch, ramp, surfaces (carpet, wood, tile, sandpaper), measuring tape.
Procedure: Release the car from the same ramp height onto the same surface and time how long it takes to travel a fixed distance. Repeat multiple times for each surface.
Variables:
- Independent: Surface type.
- Dependent: Time/speed.
- Controlled: Ramp height, car, distance.
Expected results: Smooth surfaces yield faster speeds; rough surfaces slow the car.
Safety & presentation tips: Use consistent release method; show average times in a bar graph.
5. How Does Acid Rain Affect Plant Health?
Grade level: Middle to high school
Aim: Simulate acid rain and study its effect on plants.
Materials: The same plant species, sulfuric acid or vinegar to adjust pH (use safe weak acids), pH meter or strips, pots, soil.
Procedure: Prepare water at different pH levels resembling normal rain and acidic rain. Water plants with these solutions over weeks and observe growth, leaf discoloration, and survival.
Variables:
- Independent: pH of watering solution.
- Dependent: Plant health indicators.
- Controlled: Plant type, soil, light.
Expected results: Lower pH (more acidic) can damage leaves and stunt growth.
Safety & presentation tips: Use very diluted acids and protective gloves. Show pH data and photos of leaf damage.
6. Which Material Is Best for Insulating a Drink (Preventing Heat Transfer)?
Grade level: Elementary to high school (adjust depth)
Aim: Compare insulation effectiveness of different materials.
Materials: Small identical cups, hot water, thermometer, insulating materials (styrofoam, aluminum foil, wool, cotton, bubble wrap), timer.
Procedure: Pour equal hot water into cups wrapped with different materials. Measure temperature decline at regular intervals (e.g., every 5 minutes for 30 minutes).
Variables:
- Independent: Insulating material.
- Dependent: Temperature drop rate.
- Controlled: Water volume, initial temperature, ambient conditions.
Expected results: Materials with trapped air (styrofoam, bubble wrap) are better insulators.
Safety & presentation tips: Use warm but not boiling water if students handle it. Plot temperature vs. time lines for each material.
7. How Does Sugar Content Affect Yeast Fermentation (Bread Dough Rise)?
Grade level: Middle school
Aim: Test how varying sugar concentrations influence yeast activity.
Materials: Active dry yeast, warm water, sugar, flour (for dough) or use fermentation in bottles, measuring devices, stopwatch.
Procedure: Prepare identical dough batches or yeast solutions with varying sugar amounts. Measure rise height or CO₂ production over time.
Variables:
- Independent: Sugar concentration.
- Dependent: Dough rise, gas production.
- Controlled: Yeast amount, temperature, mixing method.
Expected results: Moderate sugar increases fermentation (food for yeast); excessive sugar may inhibit yeast due to osmotic pressure.
Safety & presentation tips: Use food-safe practices; present a chart showing rise over time.
8. Which Toothpaste Formula Removes Stains Best?
Grade level: Middle school
Aim: Compare stain removal properties of different toothpaste types (whitening, regular, natural).
Materials: Tea- or coffee-stained eggshells or white cloth, toothpastes, toothbrushes, timer, water.
Procedure: Rub stained surfaces with each toothpaste for the same time and force, rinse, and compare before-and-after color using photos or color charts.
Variables:
- Independent: Toothpaste type.
- Dependent: Stain reduction.
- Controlled: Time and pressure of brushing, stain source.
Expected results: Whitening formulas may show stronger stain removal due to abrasive agents or chemicals.
Safety & presentation tips: Do not ingest; wear gloves. Use close-up photos and quantify stain reduction (e.g., colorimeter app or visual scale).
9. How Do Different Salt Concentrations Affect Water Density and Floating?
Grade level: Middle school
Aim: Show how salt changes water density and object buoyancy.
Materials: Transparent containers, water, varying amounts of salt, eggs or small fruits, scale.
Procedure: Prepare water with increasing salt concentrations and float an egg or fruit to find at which concentration it floats versus sinks. Measure density if possible.
Variables:
- Independent: Salt concentration.
- Dependent: Buoyancy (float/sink).
- Controlled: Container size, temperature.
Expected results: Higher salt concentration increases density and makes objects more buoyant.
Safety & presentation tips: Label concentrations; include a graph of salt concentration vs. float height.
10. How Effective Are Different Natural Antibacterial Agents (Garlic, Honey, Lemon)?
Grade level: High school (microbiology rules apply)
Aim: Compare antibacterial activity of natural substances against non-pathogenic bacteria (e.g., safe lab strain or yogurt bacteria).
Materials: Agar plates, safe bacteria strain (or use yeast), sterile swabs, small filter paper discs soaked in substances, incubator or warm environment.
Procedure: Spread bacteria evenly on agar plates. Place discs soaked in garlic extract, honey solution, lemon juice, and a control (water). Incubate and measure inhibition zones.
Variables:
- Independent: Antibacterial agent.
- Dependent: Zone of inhibition size.
- Controlled: Bacterial concentration, disc size, incubation time.
Expected results: Some natural agents (garlic, honey) often show antibacterial effects.
Safety & presentation tips: Follow school lab safety. Use safe microbes only and sterile technique. Photograph plates and measure inhibition diameters.
11. How Does the Angle of a Solar Panel Affect Its Power Output?
Grade level: Middle to high school
Aim: Test power output at different panel angles relative to light source.
Materials: Small solar panel, multimeter, lamp or sunlight, protractor, stand.
Procedure: Point the panel at a light source at different angles (0°, 15°, 30°, 45°, 60°, etc.), measure voltage/current, and calculate power. Record readings at same time of day/light intensity.
Variables:
- Independent: Panel angle.
- Dependent: Voltage/current (power).
- Controlled: Light intensity, distance.
Expected results: There will be an optimal angle that maximizes power; typically perpendicular to light source is best.
Safety & presentation tips: In sunlight, protect devices from overheating. Present a power vs. angle curve.
12. Do Different Types of Music Affect Plant Growth?
Grade level: Middle school
Aim: Investigate whether sound/music influences plant growth.
Materials: Identical plants, speakers, playlists (classical, rock, silence/control), ruler, timer.
Procedure: Expose groups of plants to specific music for set hours each day. Measure growth, leaf count, and health over weeks.
Variables:
- Independent: Music type.
- Dependent: Plant growth metrics.
- Controlled: Light, water, potting soil.
Expected results: Effects are often small and controversial; but some studies suggest classical may be favorable.
Safety & presentation tips: Keep volume moderate. Use audio logs and growth charts.
13. How Do Different Cleaning Agents Affect Bacteria on Surfaces?
Grade level: High school (follow lab safety)
Aim: Compare household cleaners’ effectiveness in reducing bacteria on common surfaces.
Materials: Sterile swabs, agar plates, safe bacteria samples (or natural swabs from surfaces), cleaning agents (soap, bleach solution, vinegar), gloves.
Procedure: Swab a surface, streak onto agar (control). Clean a similar surface with a specified cleaner, swab, and plate. Incubate safely and compare bacterial growth.
Variables:
- Independent: Cleaning agent.
- Dependent: Bacterial colony count.
- Controlled: Surface type, swabbing method, incubation time.
Expected results: Bleach or disinfectants tend to show the largest reduction; soap physically removes bacteria.
Safety & presentation tips: Use safe practices and non-pathogenic organisms. Explain real-world implications like sanitation.
14. Can You Make a Simple Water Filter and How Well Does It Work?
Grade level: Elementary to middle school
Aim: Build filters from materials and test how well they remove particulates and reduce turbidity.
Materials: Plastic bottles, sand, gravel, activated charcoal, cotton, dirty water (soil + water), turbidity tube or visual comparison, measuring cups.
Procedure: Layer materials in a cut bottle to create a filter. Pour dirty water through and compare clarity before and after. Measure time to filter and amount of improvement.
Variables:
- Independent: Filter layers/materials.
- Dependent: Turbidity/clarity and filtration time.
- Controlled: Amount of dirty water, flow rate.
Expected results: Activated charcoal helps remove odors and fine particles; layered gravel and sand remove larger particles.
Safety & presentation tips: Use gloves when handling dirty water. Display before-and-after photos and explain limitations.
15. Which Brand of Phone Screen Protector Reduces Fingerprints Best?
Grade level: Middle school
Aim: Compare fingerprint visibility on different screen protector types.
Materials: Identical phone screens or tempered glass samples, fingerprint oils (or natural finger), camera, light, cleaning cloths.
Procedure: Touch each protector a fixed number of times. Photograph under consistent lighting and rate fingerprint visibility visually or using image analysis.
Variables:
- Independent: Protector type (matte, glossy, oleophobic coatings).
- Dependent: Fingerprint visibility.
- Controlled: Number of touches, lighting.
Expected results: Oleophobic coatings or matte finishes reduce visible fingerprints.
Safety & presentation tips: Use non-damaging test surfaces. Show side-by-side photos.
16. How Do Different Types of Balloons Affect Static Electricity Attraction?
Grade level: Elementary to middle school
Aim: Test how material affects static charge and attraction to small objects.
Materials: Balloons (latex, Mylar), wool cloth, small paper bits or confetti, ruler.
Procedure: Inflate balloons, rub with wool for the same time, and hold near paper bits to count attracted pieces and distance at which attraction starts.
Variables:
- Independent: Balloon material.
- Dependent: Number of attracted pieces/distance.
- Controlled: Rubbing time, environment humidity.
Expected results: Latex works well for static; humidity reduces static charge.
Safety & presentation tips: Avoid overinflation; present average counts and humidity notes.
17. Which Bread Preservative Method Works Best (Refrigeration, Salt, or Vinegar)?
Grade level: Middle school
Aim: Observe mold growth on bread using different preservation methods.
Materials: Slices of bread, plastic bags, refrigerator, salt solution, vinegar solution, petri dishes (optional), timer.
Procedure: Treat slices with different methods, store under same conditions, and observe mold growth daily for 1–2 weeks. Photograph and record time until first visible mold.
Variables:
- Independent: Preservation method.
- Dependent: Time to mold onset and mold spread.
- Controlled: Bread brand, storage container.
Expected results: Refrigeration slows mold; vinegar (acid) may delay mold compared to control.
Safety & presentation tips: Handle mold carefully and dispose safely in sealed bags.
18. How Do Different Materials Affect the Speed of Sound?
Grade level: Middle to high school
Aim: Compare sound travel through air, water, and solid materials.
Materials: Stopwatch, long rod or metal pipe, water tank, tapping object, microphone (optional), measuring tape.
Procedure: Create sound at one end of a material and detect time to reach a listener or sensor at the other end. Compare times per distance for different materials.
Variables:
- Independent: Medium (air, water, metal).
- Dependent: Speed/time for sound travel.
- Controlled: Distance, same sound source.
Expected results: Sound travels fastest in solids, slower in liquids, slowest in gases.
Safety & presentation tips: Keep volumes safe. Present calculated speeds with comparison to standard values.
19. How Does Sugar Type (Glucose, Fructose, Sucrose) Affect Crystal Formation (Candy Crystals)?
Grade level: Middle to high school
Aim: Compare crystallization rate and crystal structure for different sugars.
Materials: Beakers, sugar types, water, heating plate (or stove with supervision), string or sticks for crystal growth, jars.
Procedure: Make saturated sugar solutions with each sugar, suspend a string, and allow crystals to form over days. Compare crystal size and formation time.
Variables:
- Independent: Sugar type.
- Dependent: Crystal size and formation time.
- Controlled: Temperature, saturation level, jar size.
Expected results: Different sugars crystallize differently; sucrose tends to form larger crystals in rock candy.
Safety & presentation tips: Supervise heating. Show photos at intervals and include crystal measurements.
20. Can You Build a Simple Periscope and Test Viewing Angles?
Grade level: Elementary to middle school
Aim: Build a periscope and test how angle affects field of view.
Materials: Cardboard tube or boxes, two mirrors at 45°, tape, protractor, ruler.
Procedure: Assemble periscope with mirrors placed at 45°. Look through and adjust mirror angles slightly to see how field of view changes. Measure how far you can see around an obstacle.
Variables:
- Independent: Mirror angle adjustments.
- Dependent: Field-of-view width or distance visible.
- Controlled: Mirror size and separation.
Expected results: 45° mirrors give a clear straight-line view; changing angle distorts view.
Safety & presentation tips: Use small mirrors carefully; show diagrams and photos of what’s seen.
21. Which Household Material Absorbs Sound Best (Soundproofing)?
Grade level: Middle to high school
Aim: Test sound absorption efficiency of materials like foam, fabric, cardboard, and blankets.
Materials: Sound source (phone speaker), decibel meter app or microphone, identical small boxes, materials, ruler.
Procedure: Place source inside boxes lined with different materials and measure outside decibel level at a fixed distance. Compare reductions.
Variables:
- Independent: Lining material.
- Dependent: Decibel reduction.
- Controlled: Source volume, distance.
Expected results: Thicker, porous materials absorb sound better (foam, blankets).
Safety & presentation tips: Keep volumes safe. Provide decibel readings and photos of setups.
22. How Does Refrigerator Temperature Affect Food Spoilage Rate?
Grade level: Middle to high school
Aim: See how different fridge temperatures change spoilage.
Materials: Identical food samples (e.g., slices of fruit or bread), refrigerator with adjustable settings, thermometer, sealed bags.
Procedure: Store identical samples at different fridge temperatures and observe mold or spoilage over time. Record days until spoilage starts.
Variables:
- Independent: Refrigerator temperature.
- Dependent: Time to spoilage.
- Controlled: Food type, packaging.
Expected results: Lower temperatures slow microbial growth and spoilage.
Safety & presentation tips: Dispose spoiled food safely. Use photos and a spoilage timeline.
23. Which Color of a Car Absorbs Heat Most Quickly?
Grade level: Middle to high school
Aim: Test temperature increase inside color-coated boxes or car models.
Materials: Small boxes painted different colors (black, white, red), thermometer, lamp (as sun).
Procedure: Place thermometer inside each box under identical lamp light and record temperature rise over time.
Variables:
- Independent: Color.
- Dependent: Temperature increase.
- Controlled: Lamp intensity, box size.
Expected results: Darker colors (black) absorb more heat; lighter colors (white) reflect more.
Safety & presentation tips: Use heat-safe materials and monitor temperature.
24. How Effective Are Composting Methods (Aerobic vs Anaerobic) for Breaking Down Food Waste?
Grade level: High school
Aim: Compare decomposition rate and odor between aerobic (with air) and anaerobic (without air) composting.
Materials: Two sealed containers, organic waste, thermometer, scale, composting starter (optional).
Procedure: Create one aerobic bin (with holes and occasional turning) and one anaerobic (sealed). Measure weight loss, temperature, and odor over weeks.
Variables:
- Independent: Composting method.
- Dependent: Decomposition rate and temperature.
- Controlled: Waste type and amount.
Expected results: Aerobic composting is typically faster and less smelly; anaerobic can produce more odor and methane.
Safety & presentation tips: Handle compost with gloves; explain environmental benefits.
25. How Does pH Affect Enzyme Activity (Using Catalase and Hydrogen Peroxide)?
Grade level: High school
Aim: Test how pH changes the activity of catalase (found in potato or liver) breaking down hydrogen peroxide.
Materials: Potato or liver extract (catalase source), hydrogen peroxide, pH buffers or vinegar/baking soda to adjust pH, graduated cylinders, stopwatch.
Procedure: Prepare solutions at different pH values, add equal amounts of catalase extract, and measure the amount of oxygen produced (foam height or gas capture) in a set time.
Variables:
- Independent: pH level.
- Dependent: Enzyme activity (rate of O₂ production).
- Controlled: Catalase amount, temperature.
Expected results: Enzymes have optimal pH; activity drops off when pH is too high or low.
Safety & presentation tips: Use dilute H₂O₂ and wear safety goggles. Graph enzyme activity vs. pH.
26. Which Recyclable Material Makes the Best Lightweight Bridge (Strength Test)?
Grade level: Middle to high school
Aim: Build small bridges from recyclable materials and test load capacity versus weight.
Materials: Cardboard, plastic bottles, popsicle sticks, glue, weights, scale, ruler.
Procedure: Construct bridges of similar dimensions from different materials. Place weights gradually and record load at failure. Measure bridge weight to calculate strength-to-weight ratio.
Variables:
- Independent: Material type.
- Dependent: Maximum load supported.
- Controlled: Bridge design and dimensions.
Expected results: Some structures (trusses) of light materials can support surprising loads; material stiffness matters.
Safety & presentation tips: Ensure safe dropping of weights. Show photos of failure modes and a table of strength-to-weight.
27. How Do Different Diets Affect Earthworm Activity?
Grade level: Middle school
Aim: Compare worm activity and health when fed different organic diets (kitchen scraps, paper, leaves).
Materials: Identical worm bins, composting worms, different food treatments, thermometer, moisture meter (optional).
Procedure: Feed each bin a different diet and measure worm activity (movement), reproduction, and waste production over weeks.
Variables:
- Independent: Diet type.
- Dependent: Worm activity and reproduction.
- Controlled: Bin size, temperature, moisture.
Expected results: Balanced, moist organic scraps produce healthier worms than dry or carbon-heavy diets.
Safety & presentation tips: Keep bins covered and ventilated. Explain ecological importance.
28. Can You Create a Battery from Fruits and Which Fruit Produces the Most Voltage?
Grade level: Elementary to middle school
Aim: Build fruit batteries and compare voltage produced.
Materials: Oranges, lemons, potatoes, copper coins/wires, zinc nails, multimeter, wires, LED (optional).
Procedure: Insert a copper and zinc electrode into each fruit. Measure voltage across electrodes with a multimeter and try to light an LED by connecting fruits in series.
Variables:
- Independent: Fruit type.
- Dependent: Voltage produced.
- Controlled: Electrode material and insertion depth.
Expected results: Citrus fruits (lemon, orange) often produce higher voltages due to acidity.
Safety & presentation tips: Use safe low-voltage handling. Show wiring diagrams and measured voltages.
29. How Does Surface Area Affect the Rate of Ice Melting?
Grade level: Elementary to middle school
Aim: Observe how ice melts faster when broken into smaller pieces (larger surface area).
Materials: Ice blocks, cups, stopwatch, scale, thermometer.
Procedure: Compare melting times for one large ice cube vs. many small cubes with identical total mass at room temperature. Record time to fully melt and temperature changes.
Variables:
- Independent: Surface area (large vs. small pieces).
- Dependent: Melting time.
- Controlled: Total ice mass, ambient temperature.
Expected results: More surface area speeds up melting due to greater exposure to warm air.
Safety & presentation tips: Ensure surfaces don’t get water damage; present time-lapse photos.
30. How Efficient Is Different Light Bulb Types at Producing Light per Watt?
Grade level: Middle to high school
Aim: Compare luminous efficiency of incandescent, CFL, and LED bulbs.
Materials: Bulbs of same wattage (or record wattage), lux meter or smartphone light meter app, power meter (optional), consistent lamp housing.
Procedure: Measure light intensity (lux) at a fixed distance when each bulb is turned on and calculate lux per watt or lumens per watt if lumens data available.
Variables:
- Independent: Bulb type.
- Dependent: Light output per watt.
- Controlled: Distance, fixture, measurement conditions.
Expected results: LEDs usually offer the highest lumens per watt, followed by CFLs and then incandescent.
Safety & presentation tips: Keep measurement consistent. Present a table and bar graph comparing efficiency.
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Conclusion
You now have 50 science fair project ideas, with 30 fully detailed projects ready to start and 20 concise prompts to expand.
These projects cover biology, chemistry, physics, environmental science, engineering, and everyday science — so there’s something for every interest and grade level.
Pick an idea that excites you, plan carefully using the scientific method, document everything, and present your results clearly.
Remember, a great project isn’t just about the final result — judges value careful planning, clear data, thoughtful analysis, and creativity. Good luck with your science fair — have fun discovering, testing, and sharing what you learn.