Learning about the heart or the circulatory system? These heart science projects will fit right in with any elementary or middle school science themes about the heart.
Many science teachers like teaching about the heart during February for Valentine’s Day (because love). Some of the experiments on this list feature fun Valentine’s Day themes like candy and hearts as part of the experiment, but not necessarily about the human heart itself.
If you love these experiments, you might also like Valentine’s Day STEM activities, Valentine’s Day STEM activities for kindergarten, or Valentine’s Day coding activities.

What are Heart Science Projects?
A heart science project is a science project that is all about the heart! There are some that are about how human hearts work, and some that just contain heart shapes (because hearts are fun!).
Both types of experiments are designed to help children better understand a scientific concept or the process of science investigation.
How to do a Heart Science Experiment

Every heart science experiment is a little different, depending on your goals.
However, there are two main purposes to any science experiment (or demonstration).
The first purpose is to demonstrate a scientific concept (like showing how the circulatory system works).
The second purpose is to show how to conduct an experiment with a hypothesis, variables, and the recording of results.
Any of the heart science projects on this list can be done as demonstrations or as experiments, depending on how you set them up.
For home science experiments, we tend to do more demonstrations to get kids excited about science. But in the classroom, we like to run the experiments as true experiments so that children get a rounded STEM education.
The Complete List of Heart Science Projects

Whether you are looking for a heart science project that is about the human heart, or just a heart science project featuring hearts, you’ll find the best collection of experiments here.
Use these science demonstrations to illustrate the scientific concepts that your class is currently learning in February.
Heart Science Experiments about the Human Heart

Learn about the chambers of the heart and the circulatory system when you make this 3D heart model from clay. You can make it as simple or as detailed as you like! Combine this model with one of the circulatory system models and make a functioning heart.
Learn about the Circulatory System
This is a comprehensive study on the complete circulatory system that is hands-on and tons of fun for kids. It’s a fun way to see how the heart connects with the entire body and how important it is!
Make a Functioning Heart Model
Make a working heart models and find out just what the heart does!
Heart Science Projects featuring Hearts

Squishy Circuits Light-Up Heart
Circuits are super cool, and squishy circuits make them accessible for kids. Learn about electrical science when you make a light-up heart!
Dancing Candy Heart Experiment
Make those candy hearts dance! This candy heart experiment is a fun twist on the classic alka-seltzer lava lamp science project.
Take science into the kitchen! Learn about states of matter and how temperature can change the state of matter in this fun and edible heart science project.
Learning about chemical reactions never gets old. Kids love fizzing and bubbling experiments. Give this one a Valentine’s Day twist with these red heart blocks.
Valentine Heart Chromatography Experiment with Markers
Find out what colors are hidden inside of non-primary colors. How many colors are actually in a black marker? What about a brown marker? Shape your filter paper into hearts and check out shades of pink and purple to make this Valentine’s Day themed.
Salt Crystal Hearts Science Experiment
Learn about crystal formations and solutions with this classic science experiment. Form your pipe cleaners into heart shapes to make fun decorations for Valentine’s Day!
Learn about how crystals form and how to make rock candy in this fun Valentine’s Day twist on the classic candy experiment.
Chasing Hearts Science Experiment
Did you know that dry erase markers float in water? This chasing hearts challenge is a fun way to combine physics with a study of the heart.
This fun Valentine’s Day science experiment teaches kids about the viscosity of liquids using hearts!
Make this density jar and drop in different Valentine hearts to see how dense they are!