70 Best High School Science Fair Projects in Every Subject

The cool thing about high school science fair projects is that kids are old enough to tackle some pretty amazing concepts. Some science experiments for high school are just advanced versions of simpler projects they did when they were younger, with detailed calculations or fewer instructions. Other projects involve fire, chemicals, or other materials they couldn’t use before.

Note: Some of these projects were written as classroom labs, but can be adapted to become science fair projects too. Just consider variables that you can change up, like materials or other parameters. That changes a classroom activity into a true scientific method experiment!

To make it easier to find the right high school science fair project idea for you, we’ve rated all the projects by difficulty and the materials needed:

Difficulty:

  • Easy: Low or no-prep experiments you can do pretty much anytime
  • Medium: These take a little more setup or a longer time to complete
  • Advanced: Experiments like these take a fairly big commitment of time or effort

Materials:

  • Basic: Simple items you probably already have around the house
  • Medium: Items that you might not already have but are easy to get your hands on
  • Advanced: These require specialized or more expensive supplies to complete

Jump to:

Biology and Life Science High School Science Fair Projects

Explore the living world with these biology science project ideas, learning more about plants, animals, the environment, and much more.

Extract DNA from an onion

Difficulty: Medium / Materials: Medium

You don’t need a lot of supplies to perform this experiment, but it’s impressive nonetheless. Turn this into a science fair project by trying it with other fruits and vegetables too.

Re-create Mendel’s pea plant experiment

Difficulty: Medium / Materials: Medium

Gregor Mendel’s pea plant experiments were some of the first to explore inherited traits and genetics. Try your own cross-pollination experiments with fast-growing plants like peas or beans.

Make plants move with light

Difficulty: Medium / Materials: Medium

By this age, kids know that many plants move toward sunlight, a process known as phototropism. So high school science fair projects on this topic need to introduce variables into the process, like covering seedling parts with different materials to see the effects.

Test the five-second rule

Difficulty: Medium / Materials: Medium

We’d all like to know the answer to this one: Is it really safe to eat food you’ve dropped on the floor? Design and conduct an experiment to find out (although we think we might already know the answer).

Find out if color affects taste

Difficulty: Medium / Materials: Medium

Just how interlinked are all our senses? Does the sight of food affect how it tastes? Find out with a fun food science fair project like this one!

See the effects of antibiotics on bacteria

Home Science Tools

Difficulty: Medium / Materials: Advanced

Bacteria can be divided into two groups: gram-positive and gram-negative. In this experiment, students first determine the two groups, then try the effects of various antibiotics on them. You can get a gram stain kit, bacillus cereus and rodospirillum rubrum cultures, and antibiotic discs from Home Science Tools.

Learn more: Antibiotics Project at Home Science Tools

Witness the carbon cycle in action

Test tubes filled with plants and green and blue liquid
Science Lessons That Rock

Difficulty: Medium / Materials: Advanced

Experiment with the effects of light on the carbon cycle. Make this science fair project even more interesting by adding some small aquatic animals like snails or fish into the mix!

Learn more: Carbon Cycle at Science Lessons That Rock

Look for cell mitosis in an onion

Difficulty: Medium / Materials: Advanced

Cell mitosis (division) is actually easy to see in action when you look at onion root tips under a microscope. Students will be amazed to see science theory become science reality right before their eyes. Adapt this lab into a high school science fair project by applying the process to other organisms too.

Test the effects of disinfectants

Petri dish divided in half with bacteria and paper disks on the surface
Amy Brown Science

Difficulty: Medium / Materials: Advanced

Grow bacteria in a petri dish along with paper disks soaked in various antiseptics and disinfectants. You’ll be able to see which ones effectively inhibit bacteria growth.

Learn more: Antiseptics and Disinfectants at Amy Brown Science

Pit hydroponics against soil

Difficulty: Medium / Materials: Medium

Growing vegetables without soil (hydroponics) is a popular trend, allowing people to garden just about anywhere.

More Life Sciences and Biology Science Fair Projects for High School

Use these questions and ideas to design your own experiment:

  • Explore ways to prevent soil erosion.
  • What are the most accurate methods of predicting various weather patterns?
  • Try out various fertilization methods to find the best and safest way to increase crop yield.
  • What’s the best way to prevent mold growth on food for long-term storage?
  • Does exposure to smoke or other air pollutants affect plant growth?
  • Compare the chemical and/or bacterial content of various water sources (bottled, tap, spring, well water) etc.
  • Explore ways to clean up after an oil spill on land or water.
  • Conduct a wildlife field survey in a given area and compare it to results from previous surveys.
  • Find a new use for plastic bottles or bags to keep them out of landfills.
  • Devise a way to desalinate sea water and make it safe to drink.

Chemistry High School Science Fair Projects

Bunsen burners, beakers and test tubes, and the possibility of (controlled) explosions? No wonder chemistry is such a popular topic for high school science fair projects!

Break apart covalent bonds

Tub of water with battery leads in it
Teaching Without Chairs

Difficulty: Medium / Materials: Medium

Break the covalent bond of H2O into H and O with this simple experiment. You only need simple supplies for this one. Turn it into a science fair project by changing up the variables—does the temperature of the water matter? What happens if you try this with other liquids?

Learn more: Covalent Bonds at Teaching Without Chairs

Measure the calories in various foods

Difficulty: Medium / Materials: Medium

Are the calorie counts on your favorite snacks accurate? Build your own calorimeter and find out! This kit from Home Science Tools has all the supplies you’ll need.

Detect latent fingerprints

Fingerprint divided into two, one half yellow and one half black
Hub Pages

Difficulty: Medium / Materials: Medium

Forensic science is engrossing and can lead to important career opportunities too. Explore the chemistry needed to detect latent (invisible) fingerprints, just like they do for crime scenes!

Learn more: Fingerprints Project at Hub Pages

Use Alka-Seltzer to explore reaction rate

Difficulty: Easy / Materials: Easy

Tweak this basic concept to create a variety of high school chemistry science fair projects. Change the temperature, surface area, pressure, and more to see how reaction rates change.

Determine whether sports drinks provide more electrolytes than OJ

Difficulty: Medium / Materials: Advanced

Are those pricey sports drinks really worth it? Try this experiment to find out. You’ll need some special equipment for this one; buy a complete kit at Home Science Tools.

Turn flames into a rainbow

Difficulty: Medium / Materials: Advanced

You’ll need to get your hands on a few different chemicals for this experiment, but the wow factor will make it worth the effort! Make it a science project by seeing if different materials, air temperature, or other factors change the results.

Discover the size of a mole

Supplies needed for mole experiment, included scale, salt, and chalk
Amy Brown Science

Difficulty: Medium / Materials: Medium

The mole is a key concept in chemistry, so it’s important to ensure students really understand it. This experiment uses simple materials like salt and chalk to make an abstract concept more concrete. Make it a project by applying the same procedure to a variety of substances, or determining whether outside variables have an effect on the results.

Learn more: How Big Is a Mole? at Amy Brown Science

Cook up candy to learn mole and molecule calculations

Aluminum foil bowl filled with bubbling liquid over a bunsen burner
Dunigan Science on TpT

Difficulty: Medium / Materials: Medium

This edible experiment lets students make their own peppermint hard candy while they calculate mass, moles, molecules, and formula weights. Tweak the formulas to create different types of candy and make this into a sweet science fair project!

Learn more: Candy Chemistry at Dunigan Science on TpT

Make soap to understand saponification

Colorful soaps from saponification science experiments for high school
Chemistry Solutions on TpT

Difficulty: Medium / Materials: Medium

Take a closer look at an everyday item: soap! Use oils and other ingredients to make your own soap, learning about esters and saponification. Tinker with the formula to find one that fits a particular set of parameters.

Learn more: Saponification at Chemistry Solutions on TpT

Uncover the secrets of evaporation

Difficulty: Medium / Materials: Medium

Explore the factors that affect evaporation, then come up with ways to slow them down or speed them up for a simple science fair project.

Learn more: Evaporation at Science Projects

More Chemistry Science Fair Projects for High School

These questions and ideas can spark ideas for a unique experiment:

  • Compare the properties of sugar and artificial sweeteners.
  • Explore the impact of temperature, concentration, and seeding on crystal growth.
  • Test various antacids on the market to find the most effective product.
  • What is the optimum temperature for yeast production when baking bread from scratch?
  • Compare the vitamin C content of various fruits and vegetables.
  • How does temperature affect enzyme-catalyzed reactions?
  • Investigate the effects of pH on an acid-base chemical reaction.
  • Devise a new natural way to test pH levels (such as cabbage leaves).
  • What’s the best way to slow down metal oxidation (the form of rust)?
  • How do changes in ingredients and method affect the results of a baking recipe?

Physics High School Science Fair Projects

When you think of physics science projects for high school, the first thing that comes to mind is probably the classic build-a-bridge. But there are plenty of other ways for teens to get hands-on with physics concepts. Here are some to try.

Remove the air in a DIY vacuum chamber

DIY vacuum chamber made from a jar and large hypodermic needle
Instructables

Difficulty: Medium / Materials: Medium

You can use a vacuum chamber to do lots of cool high school science fair projects, but a ready-made one can be expensive. Try this project to make your own with basic supplies.

Learn more: Vacuum Chamber at Instructables

Put together a mini Tesla coil

Difficulty: Medium / Materials: Medium

Looking for a simple but showy high school science fair project? Build your own mini Tesla coil and wow the crowd!

Boil water in a paper cup

Difficulty: Medium / Materials: Medium

Logic tells us we shouldn’t set a paper cup over a heat source, right? Yet it’s actually possible to boil water in a paper cup without burning the cup up! Learn about heat transfer and thermal conductivity with this experiment. Go deeper by trying other liquids like honey to see what happens.

Build a better lightbulb

Difficulty: Medium / Materials: Medium

Emulate Edison and build your own simple light bulb! You can turn this into a science fair project by experimenting with different types of materials for filaments.

Measure the speed of light—with your microwave

Difficulty: Medium / Materials: Medium

Grab an egg and head to your microwave for this surprisingly simple experiment! By measuring the distance between cooked portions of egg whites, you’ll be able to calculate the wavelength of the microwaves in your oven, and in turn, the speed of light.

Generate a Lichtenberg figure

Lichtenberg figure generated on a sheet of Plexiglass
Science Notes

Difficulty: Medium / Materials: Advanced

See electricity in action when you generate and capture a Lichtenberg figure with polyethylene sheets, wood, or even acrylic and toner. Change the electrical intensity and materials to see what types of patterns you can create.

Learn more: Lichtenberg Figure at Science Notes

Explore the power of friction with sticky note pads

Difficulty: Medium / Materials: Basic

Ever try to pull a piece of paper out of the middle of a big stack? It’s harder than you think it would be! That’s due to the power of friction. In this experiment, students interleave the sheets of two sticky note pads, then measure how much weight it takes to pull them apart. The results are astonishing!

Build a cloud chamber to prove background radiation

Difficulty: Medium / Materials: Advanced

Ready to dip your toe into particle physics? Learn about background radiation and build a cloud chamber to prove the existence of muons.

Measure the effect of temperature on resistance

A beaker with a tungsten rod, connected to a multimeter
Science Project

Difficulty: Medium / Materials: Advanced

This is a popular and classic science fair experiment in physics. You’ll need a few specialized supplies, but they’re pretty easy to find.

Learn more: Temperature and Resistance at Science Project

Launch the best bottle rocket

Difficulty: Medium / Materials: Advanced

A basic bottle rocket is pretty easy to build, but it opens the door to lots of different science fair projects. Design a powerful launcher, alter the rocket so it flies higher or farther, or use only recycled materials for your flyer.

More Physics Science Fair Projects for High School

Design your own experiment in response to these questions and prompts.

  • Determine the most efficient solar panel design and placement.
  • What’s the best way to eliminate friction between two objects?
  • Explore the best methods of insulating an object against heat loss.
  • What effect does temperature have on batteries when stored for long periods of time?
  • Test the effects of magnets or electromagnetic fields on plants or other living organisms.
  • Determine the best angle and speed of a bat swing in baseball.
  • What’s the best way to soundproof an area or reduce noise produced by an item?
  • Explore methods for reducing air resistance in automotive design.
  • Use the concepts of torque and rotation to perfect a golf swing.
  • Compare the strength and durability of various building materials.

Engineering High School STEM Fair Projects

Many schools are changing up their science fairs to STEM fairs, to encourage students with an interest in engineering to participate. Many great engineering science fair projects start with a STEM challenge, like those shown here. Use these ideas to spark a full-blown project to build something new and amazing!

Solve a current environmental issue

Difficulty: Medium / Materials: Medium

A science fair project can also be an entry to the Slingshot Challenge. Produce a 1-minute video by February 1, 2024, with a solution to a current environmental problem (think: uniting creative waste reducers on social media or rehabilitating forests affected by fire) for the chance to receive up to $10,000 in funding.

Construct a model maglev train

Maglev model train built from magnets and wood craft sticks on green felt
Supermagnete

Difficulty: Medium / Materials: Medium

Maglev trains may just be the future of mass transportation. Build a model at home, and explore ways to implement the technology on a wider basis.

Learn more: Maglev Model Train at Supermagnete

Design a more efficient wind turbine

Difficulty: Medium / Materials: Medium

Wind energy is renewable, making it a good solution for the fossil fuel problem. For a smart science fair project, experiment to find the most efficient wind turbine design for a given situation.

Re-create Da Vinci’s flying machine

Da Vinci flying machine built from a paper cup and other basic supplies
Student Savvy

Difficulty: Medium / Materials: Medium

Da Vinci sketched several models of “flying machines” and hoped to soar through the sky. Do some research into his models and try to reconstruct one of your own.

Learn more: Da Vinci Flying Machine at Student Savvy

Design a heart-rate monitor

Difficulty: Medium / Materials: Medium

Smartwatches are ubiquitous these days, so pretty much anyone can wear a heart-rate monitor on their wrist. But do they work any better than one you can build yourself? Get the specialized items you need like the Arduino LilyPad Board on Amazon.

Race 3D printed cars

Simple 3-D printed race cars with vegetables strapped to them (Science Experiments for High School)
Instructables

Difficulty: Medium / Materials: Advanced

3D printers are a marvel of the modern era, and budding engineers should definitely learn to use them. Use Tinkercad or a similar program to design and print race cars that can support a defined weight, then see which can roll the fastest! (No 3D printer in your STEM lab? Check the local library. Many of them have 3D printers available for patrons to use.)

Learn more: 3D Printed Cars at Instructables

Grow veggies in a hydroponic garden

Vertical hydroponic garden made from PVC pipes and aluminum downspouts
Instructables

Difficulty: Medium / Materials: Medium

Hydroponics is the gardening wave of the future, making it easy to grow plants anywhere with minimal soil required. For a science fair STEM engineering challenge, design and construct your own hydroponic garden capable of growing vegetables to feed a family. This model is just one possible option.

Learn more: Hydroponics at Instructables

Grab items with a mechanical claw

KiwiCo hydraulic claw kit (Science Experiments for High School)
KiwiCo

Difficulty: Medium / Materials: Medium

Delve into robotics with this engineering project! This kit includes all the materials you need, with complete video instructions. Once you’ve built the basic structure, tinker around with the design to improve its strength, accuracy, or other traits.

Learn more: Hydraulic Claw at KiwiCo

Construct a crystal radio

Homemade crystal radio set (Science Experiments for High School)
SciToys

Difficulty: Medium / Materials: Advanced

Return to the good old days and build a radio from scratch! This makes a cool science fair project if you experiment with different types of materials for the antenna. It takes some specialized equipment, but fortunately, Home Science Tools has an all-in-one kit for this project.

Learn more: Crystal Radio at SciToys

Build a burglar alarm

Simple electronic burglar alarm with a cell phone
Instructables

The challenge? Set up a system to alert you when someone has broken into your house or classroom. This can take any form students can dream up, and you can customize this STEM high school science experiment for multiple skill levels. Keep it simple with an alarm that makes a sound that can be heard from a specified distance. Or kick it up a notch and require the alarm system to send a notification to a cell phone, like the project at the link.

Learn more: Intruder Alarm at Instructables

Walk across a plastic bottle bridge

Students sitting on a large bridge made of plastic bottles
Instructables

Difficulty: Medium / Materials: Medium

Balsa wood bridges are OK, but this plastic bottle bridge is really impressive! In fact, students can build all sorts of structures using the concept detailed at the link. It’s the ultimate upcycled STEM challenge!

Learn more: TrussFab Structures at Instructables

Looking for more science content? Check out the Best Science Websites for Middle and High School.

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