Find Inspiration With These Science Fair Topic Ideas

7 Categories to Inspire Projects

Science can be an intimidating topic for some kids. Between all the theories and the experiments, it can quickly become a vast and overwhelming endeavor—especially if they have been tasked with coming up with a science fair project.

Science Fair Topics

Typically, elementary school and middle students’ science fair topic ideas fall into one of seven main categories. These include the following:

  • Biology
  • Chemistry
  • Earth Science
  • Electronics
  • Astronomy
  • Engineering
  • Physics.

Looking for inspiration in one of these areas may help your child come up with a project that they can be excited about (and learn from). Here is what you need to know about each topic.



Girl explaining her science project to brother
Tooga / Getty Images

Biology is the study of living things and how they grow. This includes plants, animals, bacteria, and fungi. Projects focused on bacteria or plants are best, as there can be ethical concerns and restrictions on using animals for science fair projects.

Project ideas can include experiments, which look at how a factor such as light, temperature, water, soil acidity, or fertilizer affects plant growth.

Using Petri dishes and agar, your child also could conduct an experiment that demonstrates bacterial and fungal growth from various sources such as hands, toothbrushes, swabs of household fixtures, or by leaving the plates uncovered in different rooms.

If your child loves to learn about living things, an experiment in biology might be right up their alley. These types of projects allow them an in-depth look at how living things interact with the world around them.



Chemistry is the study of substances and what happens when you combine them to create compounds. Chemistry projects often require parent supervision.

If an experiment requires your child to use any chemicals, take precautions. Know what substances can and can't be mixed. Have water and even a fire extinguisher on hand, and make sure your child wears appropriate safety gear, such as gloves, safety goggles, and/or an apron or lab coat.

Growing crystals and exploring the effects of temperature and moisture on the growth rate is one project idea. Testing the pH of various drinks, fruit juices, water, and vinegar can explore acidity and alkalinity.

The traditional vinegar-and-baking-soda volcano is another fun chemistry experiment that can overlap with earth science.

If your child enjoys developing hypotheses and doing experiments, they may enjoy a science fair project involving chemistry. These types of projects often include performing experiments and recording data. They are especially interesting for kids who enjoying reasoning and problem-solving combined with a little hands-on experimentation.


Earth Science

Earth science encompasses kid-friendly topics including weather, climate, volcanoes, fossils, rocks, and the ocean. A project focus might include an analysis of where certain types of weather occur and what common factors produce that weather phenomenon.

A child also could explore different types of rocks and minerals and where they may be found. They also might enjoy researching energy resources and developing a project around those topics.

Or, they might want to do a project on geological disasters such as earthquakes, floods, volcanic eruptions, and landslides. Or maybe they would be interested in researching and presenting ideas on groundwater or sustainability.

Kids who are fascinated with natural disasters, the weather, the natural world, or climate change may enjoy a science fair project involving earth science. Depending on their topic, their project could involve research, experimentation, and recommendations and as well as opportunities for creating a cool display.



Electronics projects look at how electricity is conducted and can be controlled. Project ideas include experiments with circuit boards and batteries, such as the classic potato battery. Older students may want to make a crystal radio.

Kids who are mechanically inclined or enjoy building or making things often enjoy electronics-based science fair projects. In more technical terms, they would be studying the design of circuits and electrons under a variety of conditions.



Astronomy is the study of the universe and all its components, including stars, planets, moons, meteors, and other celestial bodies. It also is the study of the light objects emit and the clues they provide about their age.

Light from distant stars and galaxies takes a long time to reach Earth, so we are actually seeing them as they appeared in the past. To many kids, this is an astonishing concept—to realize that when we look at the stars, we are in effect looking back in time.

Kids who are fascinated by light or time might find an astronomy-themed science fair project intriguing. They might want to look into projects that combine the ages of stars and the concept of light years.

A child interested in this topic area might build a sundial and explain why it works. Or they could study star charts and current astronomical conditions and planet positions to prompt project ideas.



Engineering involves designing, creating, and studying the function of machines and their processes. An engineering project might involve designing a machine with an entirely new function using various simple machines in the process, such as a Rube Goldberg machine.

Kids who enjoy taking science-based knowledge combined with innovative thinking, problem-solving, and construction skills to build something that solves a problem or makes like easier for people would enjoy an engineering project.



Physicists study matter and energy. This may sound complicated until you know that this includes light, sound, magnetism, and motion.

The egg-in-a-bottle experiment is a classic in which paper is burned in the bottom of a bottle and an egg at the mouth of the bottle is drawn into it due to the change in pressure.

Making rockets or finding the best shape for a paper airplane can be fun physics projects as well. A child can also explore materials that conduct heat the best or that are the best insulators. Even studying the refraction of light through various household substances might be an interesting physics experiment.

Kids who are strong in mathematics, reasoning, and problem-solving typically enjoy science projects involving physics. Some key physics topics to explore further include electricity and magnetism, space and time, thermodynamics, quantum physics, relativity, geophysics and fluid dynamics.

A Word From Verywell

When it comes to finding a science fair project for your child, it is important to allow them to take an active role in the decision-making process. After all, they should be doing the majority of the work (except when your supervision is required). They also need to pick a topic that they will feel passionate about studying and then sharing.

Prioritize what your child will learn from participating in the science fair over developing a project that will win an award. In addition to deepening a child's knowledge on a particular topic, science fair projects help to hone their research and problem-solving skills. Keep your focus on those aspects and you both are likely to enjoy the experience.