Science Fair Project Ideas for Middle School: 36 Ideas for 6th, 7th and 8th Grade

Last updated: October 30, 2026

A good middle school science fair project starts with a question your child can test, not a topic they can describe. "Volcanoes" is a topic. "Does the amount of baking soda change how high the foam rises?" is a question with one thing to change and one thing to measure. Below are 36 project ideas for 6th, 7th and 8th grade, each written as a testable question. They are grouped by subject and chosen so a student can run them at home or at school with ordinary materials. We also explain the rules that quietly disqualify some of the most popular projects, and how to plan the work so it is finished before fair season.

Does your middle schooler want to work on real STEM questions with an expert? See if your child qualifies for the STEM Explorers Program →

What makes a good science fair project

Judges and teachers look for the same things at every level: a clear question, a fair test and honest results. In practice that means:

One variable at a time. Change one thing (the independent variable), measure one result (the dependent variable), and keep everything else the same.
Something you can measure with a number. Height in centimeters, time in seconds, mass in grams. "Looks better" is hard to judge; "dissolved 40 percent faster" is not.
Repeated trials. Run each condition several times and average the results, so one odd result does not decide the outcome.
A logbook. Write down every trial, every date and every mistake as it happens. A logbook shows the work behind the poster.
A question your child actually cares about. Interest carries a student through the boring parts, such as the fifth trial of the same test.

Check the rules before you choose

Many local fairs follow the International Rules for Pre-college Science Research, published every year by Society for Science. These are the official rules for Regeneron ISEF and for students competing at Society-affiliated fairs, including the middle school fairs that lead to the Thermo Fisher Scientific Junior Innovators Challenge. Your school fair may use simpler rules, but if your child's project could move up to a regional or state fair, plan for these from the start.

Three rules catch the most middle school projects:

Growing bacteria at home is prohibited. The 2026–2027 rules say that culturing potentially hazardous biological agents, "even BSL-1 organisms," is prohibited in a home environment. The classic "which surface in my house has the most germs" project, where a student swabs a phone and grows the sample in a petri dish, breaks this rule. Samples may be collected at home only if they go straight to a laboratory approved by the fair's Scientific Review Committee.
Projects with people need approval first. Surveys, taste tests, reaction-time tests and memory tests all count as research with human participants. Under the International Rules, these must be approved by an Institutional Review Board (IRB) before the student starts, and participants must give informed consent.
Projects with vertebrate animals need approval first. That includes fish and pets. Projects with plants, yeast, and mold on food are simpler: studying mold growth on food is exempt from prior review if the experiment stops at the first evidence of mold, and fermentation with baker's yeast is exempt too, though both still need a short risk assessment form.

Every idea below avoids people, vertebrate animals and cultured bacteria, so most students can start right away. If your child wants to do a project with people, talk to the teacher in charge of the fair before collecting any data.

Physics and engineering project ideas

How does a tennis ball's temperature affect how high it bounces?
Does the angle of a ramp change how far a toy car rolls after it leaves the ramp?
Which paper airplane design flies farthest, and does wing area or weight matter more?
How does the number of wire turns in a coil change how many paper clips an electromagnet can lift?
Which blade shape makes a small wind turbine produce the most voltage?
Does the color of a surface change how fast it warms up in sunlight?
How does water depth affect the speed of a wave in a tray?
Which insulating material keeps an ice cube frozen the longest?
How does string length change the time a pendulum takes to swing? Compare your results to the textbook formula.
Does a ball's air pressure change how far it travels when launched the same way each time?

Students in the STEM Explorers Program work one-on-one with a STEM mentor from a top-20 university. See if your child qualifies for the STEM Explorers Program →

Chemistry project ideas

How does water temperature affect how fast sugar dissolves?
Which antacid tablet neutralizes the most vinegar?
Does breaking an effervescent tablet into pieces change how fast it reacts?
Which natural indicator (red cabbage, beet juice or turmeric) shows pH changes most clearly?
How does the amount of salt in water change the temperature at which it freezes?
Which household solution removes the most tarnish from old pennies?
Which coating (lemon juice, salt water or honey water) slows the browning of cut apple slices the most?
How does temperature affect how long a glow stick glows?

Plant, biology and environment project ideas

Do radish seeds sprout faster under different colors of light?
How does salt in the water affect the growth of bean plants?
Does the acidity of water (using diluted vinegar) change how many seeds sprout?
Which mulch keeps soil moist the longest?
How does temperature affect how much gas yeast produces? Measure it with a balloon over the bottle.
How many days does bread take to show the first sign of mold at different temperatures? Stop each trial at the first visible mold.
Which homemade filter (sand, gravel or charcoal) makes muddy water clearest? Measure clarity with a flashlight and a light meter app, and never drink the water.
Do leaves with more surface area lose more water? Cover leaves with clear plastic bags and measure the water collected.
How does the slope of a tray of soil affect how much soil washes away in a model rainstorm?
Does planting grass seed on a model hillside reduce erosion?

Admitted STEM Explorers students choose a topic with their mentor by week four, then create a research paper, software project or portfolio. See if your child qualifies for the STEM Explorers Program →

Earth science and energy project ideas

How does the angle of a small solar panel change its output over a day?
Which roof color keeps a model house coolest in the sun?
Does a layer of insulation in a model house reduce how fast it cools at night?
How does the shape of a container affect how fast water evaporates from it?

Computer science and data project ideas

These need a computer, not a lab, and are a good fit for students who like coding or math.

Can a simple program predict tomorrow's high temperature better than the rule "same as today"? Use your local weather records.
Which sorting algorithm is fastest as lists get longer? Time bubble sort, insertion sort and merge sort on lists of 100, 1,000 and 10,000 numbers.
How common are long streaks in coin flips? Simulate 10,000 sets of 100 flips and compare the results to what people guess.
Does a longer password take much longer to crack? Write a small program that guesses short passwords by brute force and time it as the length grows.

For more advanced ideas, including some for 8th graders ready to work like high school researchers, see our list of research topics for high school students, which ends with a section for middle school.

How to plan a project from start to fair day

Most science fairs in the United States are held from January through March, according to Society for Science, so a project started in the fall has time to be done well. A simple plan:

Weeks 1–2: choose the question. Pick two or three ideas, check the rules above and choose one your child can test at least 3 to 5 times per condition.
Week 3: write the plan. List materials, the variable to change, the result to measure and what stays the same. Some fairs require a written research plan before any testing.
Weeks 4–7: run the trials. Record everything in the logbook, including results that look wrong.
Week 8: analyze. Make a table and a graph. Ask whether the difference is bigger than the normal variation between trials.
Weeks 9–10: write and build the board. Question, hypothesis, method, results, conclusion and what you would do next.
Before the fair: practice the talk. Judges ask questions. A student who can explain why a trial failed often impresses more than one with perfect results.

Where a middle school project can go next

A strong project can move beyond the school fair. Fairs affiliated with Society for Science can nominate the top 10 percent of their 6th, 7th and 8th grade participants for the Thermo Fisher Scientific Junior Innovators Challenge, which the Society calls "the premier STEM research competition" for these grades in the United States. Nominees then complete an online application. In 2026, the application period ran from February 1 to June 10, 1,997 students entered, and the Society named a Top 300 and then 30 finalists.

To see if a fair near you is affiliated, use the Society's Find-a-Fair directory. Affiliated fairs appear as they complete the annual affiliation process each fall.

Want your child to go beyond a one-time project and work on a real question with a mentor? See if your child qualifies for the STEM Explorers Program →

After the science fair

For many students, the science fair is the first time they ask their own question and answer it with evidence. If your child enjoyed that, there are ways to go further: a longer project with a mentor, a summer program or a math or science competition. Our guides to how to get into research in middle school, programs for gifted middle school students and summer programs for middle school students cover the options.

Frequently asked questions

What is a good science fair project for middle school? A good project tests one clear question with one variable, uses measurements you can record as numbers, and can be repeated several times. Examples: how temperature affects how fast sugar dissolves, or which insulating material keeps ice frozen longest.

What science fair projects are easy for 6th grade? Projects with simple materials and quick trials work well: dissolving sugar at different temperatures, comparing paper airplane designs, testing which mulch keeps soil moist, or seeing which coating slows the browning of apple slices.

What are good 8th grade science fair projects? 8th graders can take on longer or more technical projects, such as building an electromagnet and measuring its strength, testing solar panel angles over a day, or writing a program that compares sorting algorithms.

Can a middle school science fair project use bacteria? Under the International Rules used by Society-affiliated fairs, culturing bacteria and other potentially hazardous biological agents at home is prohibited, even for low-risk organisms. Such projects must be done in an approved laboratory. Check your own fair's rules.

Can I do a survey for my science fair project? Yes, but under the International Rules, surveys and other studies with people must be approved by an Institutional Review Board before you start, and participants must give informed consent. Ask your teacher about the approval process early.

How many trials should a science fair project have? There is no single rule, but several trials per condition (at least 3 to 5) make results more reliable than a single test.

Sources

About learnSTEM

All bright students reach a point where school stops challenging them. learnSTEM provides that challenge: the space to explore a field of their choice, guided by a world-class PhD mentor from a top-20 university, completely one-on-one and on your own schedule. Students finish with a passion for a new subject, a research project they are proud of, and a clear sense of what they want to pursue next.

See if your child qualifies for the STEM Explorers Program → · Questions about eligibility? Contact us →

"It has only strengthened my love for learning about the world and given me a paper that I am proud to say I've made." — learnSTEM student