15 Awesome Science Fair Project Ideas

Sprout Home

Building a sprout house offers an excellent lesson in biology, ecology, and a touch of leafy-thumb wonder! Create individual sprout homes—or entire sprout towns and cities if your young scientists are especially ambitious—and observe them as they develop. Children from 4 to 9 can enjoy this craft, which is simple to adjust for either a basic or more challenging experience.

Sprout Home from The Stem Laboratory

Motion Sand

Prepare this homemade kinetic sand as an independent activity for exploring chemistry. Alternatively, take the experiment further—quite literally—and introduce physics by constructing some amazing sandcastles! We suggest this project for kids between 7 and 10 years old.

Motion Sand from The Spruce

Popsicle Stick Catapult

Enjoy some hands-on momentum with this physics-based catapult project. Use a simple homemade mini catapult to send pom poms and other tiny, cushioned items as far as possible. This activity is best suited for children ages 5 and older.

Popsicle Stick Catapult from Coffee Cups and Crayons

Cosmos in a Jar

This project is incredibly simple and works wonderfully as a self-guided activity for older children. Read about space science to discover more about nebulae and black holes, then create this bottle galaxy as a charming display. We suggest this craft for children ages 3 and up. Although younger children can easily complete it, tweens will particularly enjoy keeping the finished piece as a fun bedroom accent well after the fair has ended.

Cosmos in a Jar from Kids Activities Blog

Playful Slime

These days, slime is a popular pastime and can be found at nearly any toy shop. However, being trendy doesn’t stop it from making an excellent science experiment. What better way to spark children’s interest in science than to demonstrate that one of their favorite playthings is also a polymer? We suggest this activity for children ages 6 and older—slime has no upper age limit!

Goofy Slime from The Spruce

Three-Dimensional Glasses

This fascinating activity teaches children about the science of light used in conventional 3D glasses. Since these homemade glasses genuinely function, you can locate simple 3D pictures online or pull out an old 3D storybook from the garage—or purchase one from a secondhand bookstore—to try them. We recommend this physics and light experiment for children ages 6 to 8.

Three-Dimensional Glasses from The Spruce

Cloud and Rain Weather Demonstration

You may not be able to create an actual storm inside, but this inventive weather model comes remarkably close. If you have aspiring meteorologists at home, it offers an engaging way to explain the process by which clouds become rain. We recommend this craft for young children ages 3 to 6 because it does not involve any “laboratory” work.

Cloud and Rain Weather Demonstration fromA Little Glue Will Work

DIY Spectroscope

Explore every shade in the rainbow using this simple homemade spectroscope. It’s an excellent project for repurposing scratched, damaged, or unused CDs and DVDs. Children ages 4 to 10 can enjoy this colorful science and physics activity.

DIY Spectroscope by Buggy and Buddy

Simple Pretend Snow

No matter if the day is warm or chilly, pretend snow makes for an entertaining, science-inspired activity. Use it as a meteorology lesson about weather or as a chemistry experiment demonstrating how baking soda and shaving cream become “snow.” For younger children, we suggest this sensory project only with close supervision to keep the mixture away from mouths and eyes; for kids ages 7 through 9, it works well as a chemistry craft.

Simple Pretend Snow from The Spruce

Names Made of Crystals

Take your homemade crystal projects to the next level by creating crystal names! Using only hand-shaped pipe cleaners, hot water, borax, and food coloring, you can form a lovely crystallized name of your own. Explain the chemistry behind this activity and the crystallization processes to your children with the useful “Behind the Science” section included in the tutorial. This craft is best suited for children between 3 and 10 years old.

Crystal Names from Playdough to Plato

Chromatography Butterflies

Explore how water molecules and colored particles separate through a science activity that also becomes a striking art project. Chromatography butterflies offer a delightful way to blend learning into playtime. For a science fair, prepare several stations and hang a clothesline where your “research findings” can be shown. We suggest this color-based science project for children ages 4 to 7.

Chromatography Butterflies from Buggy and Buddy

Paper Plate Clock

For children who are beginning to learn how to read a clock, this makes an ideal STEM-inspired craft. An easypaper craft with a useful purpose, ask your children to move the hour and minute hands to various times and see how confidently they can read an analog clock. We suggest this counting activity for children ages 7 to 8, or for any time your kids are studying clocks in school.

Paper Plate Clock by The Spruce

Lava Lamp

You may recall this funky little project from your own science-fair years—an easy lava lamp to make at home! Explore the science of chemical density using only oil, food coloring, water, and a few reused water bottles. We suggest this activity for children ages 7 to 9.

Lava Lamp by Little Bins for Little Hands

Bubble Blowing Mixture

Did you think blowing bubbles was only an entertaining summer pastime? It can also become an excellent science-fair experiment. This chemistry activity is recommended for children ages 6 to 8.

Bubble Blowing Mixture by The Spruce

Bouncy Balls

Turn playtime into a lesson with this project, which combines chemistry and physics. Guide your children as they blend the ingredients to form the balls, then explain why certain balls rebound while others fall and remain still. We recommend this activity for kids ages 5 and older.