LEGO Balance Scale STEM Project For Kids

Robots, racing cars, contraptions, and more — these genius LEGO stem ideas can be made with bricks you already own! We have cool LEGO project ideas that you’ll want to try right now. So go get your LEGO set because we’re about to get started!

Genius LEGO Inventions With Bricks You Already Have Book
This book is the PERFECT gift for kids of ALL ages that love building and creating new worlds with LEGOs!

LEGO Balance Scale STEM Project

My favorite part about this activity book is that each activity comes with a lesson. The project I am about to show you introduces kids to the science concept of mass versus weight by building a LEGO balance scale.

This post contains affiliate links.

Related: Speaking of building…Learn how to build a robot for kids!

LEGO Balance Scale Stem Project
There are so many things you can do with LEGOs, but today we are doing creative STEM activities that will make your child feel like a scientist!

Supplies You Need To Build a LEGO Scale:

  • 12 — 1 x 6 bricks
  • 6 — 1 x 4 bricks
  • 4 — 1 x 2 bricks
  • 1 — 6 x 12 plate
  • 4 — 4 x 6 plates
  • 2 — 1 x 16 Technic bricks
  • 9 — 2 x 4 bricks
  • 2 — 2 x 4 plates
  • 1 — 2 x 2 brick with a pin on each side

Direction To Make A Lego Scale

Step 1

Start by building the pans for the balance.

Step 2

Place two of the 4 x 6 plates side by side.

Step 3

Create a perimeter to lock them together using six 1 x 6 bricks, 2 1 x 4 bricks, and 2 1 x 2 bricks.

Step 4

Repeat with the other plates and bricks so you have two pans.

Step 5

Next, stack nine 2 x 4 bricks into a tower to create the base of the scale.

Step 6

Place the 2 x 2 brick with two pins at the top of your tower.

Step 7

Now, attach the two 1 x 16 Technic bricks to the pins and place a 2 x 4 plate on each end at the top to balance the weight.

Step 8

Add a 1 x 4 brick beneath the Technic bricks at each end to create an attachment for the pans.

Step 9

Finally, attach the pans to the scale using the 1 x 4 bricks you placed in the last step.

LEGO balance scale
Here are a couple of things you can do with LEGO bricks: LEGO spaceships, LEGO shoes, and even LEGO soap! Just check out our LEGO dedicated page to find all of these activities and more.

Now use your LEGO balance scale to try some experiments. Can you balance a set of rocks and marbles? What happens when you move the fulcrum from the middle of the scale to one of the sides? The possibilities are endless!

LEGO balance scale
Building this LEGO balance scale was so much fun and a great experiment for kids who are already interested in engineering!

This simple project is just one example of the awesome tutorials found in Genius LEGO Inventions. You can purchase Genius LEGO Inventions on Amazon and at bookstores today!

Awesome Genius LEGO Inventions

We’ve always adored Page Street Publishing and their super awesome books for kids, so we are so excited to partner with them to share about the new book, Genius LEGO Inventions with Bricks You Already Have.

If your kid is LEGO obsessed, you need this book. It’s not only a great guide to building super cool things, but it’s also a great guide to building super cool things THAT MOVE.

I’m always looking for new LEGO build ideas, so that’s why this book was a life-saver to keep my little ones doing educational but fun LEGO STEM activities.

You’ll find step-by-step directions on how to make everything from mechanical robots to eye-rolling dogs to sophisticated marble runs. And the coolest part is that each tutorial uses common LEGO bricks so you can easily build the creations for yourself. They are PERFECT for a LEGO science fair projects to show off at school (or even to friends, why not?)

More LEGO Activities From Kids Activities Blog:

How did your LEGO scale turn out? Let us know in the comments below, we’d love to hear from you.


  1. I cannot afford to subscribe right now but you offer so many freebies that I can use to teach my grandson. I want to tank you for your generosity.

    1. Kristen Yard says:

      You are so welcome! We hope that you and your grandson enjoy them! 🙂

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