How To Change Brush Size In GIMP {3 Ways}


Prefer watching tutorials? Check out the above video from my Youtube channel.



Brushes are essential for all your artwork. Today, you’ll learn 3 different ways to alter the brush size in GIMP. This includes changing via 

  1. the tool options
  2. with keyboard shortcuts
  3. with your mouse wheel

If you’re ready to learn how to adjust your brush size in GIMP, let’s do it!

If needed, here’s how to install free pre-made brushes in GIMP.

Table of Contents

How To Increase the Brush Size, Option 1

tool options

This first method for adjusting the size of your brush is through the tool options. Select your brush, and look inside the tool options. Locate the slider labeled; Size.

Of the three options for resizing, this is the slowest method to use.

How To Adjust the Paintbrush Size, Option 2

Your next option for resizing is via the keyboard shortcuts. These “keys” will work for both Mac and PC users.

The shortcut is your bracket keys. The left ( [ ) bracket will make your brush smaller, and the right ( ] ) will make your brush larger.

This will increase the paintbrush size by a 1px radius at a time! Speed up the resize with “Shift + [ or ]” to increase or decrease by a 10px radius.

{My Favorite Way To} Adjust the Brush Size, Option 3

Although the second option is pretty quick, this method is even faster! To use this option, you’ll need a mouse with a scroll wheel. If you have one, just scroll away!

Is the Mouse Wheel Not Adjusting Your Brush?

If your mouse wheel doesn’t resize the brush as you had expected, there’s an easy fix. Navigate to the Preferences to set up your mouse wheel for adjusting the brush size;

Locate “Input Devices” and expand the option. Inside, you’ll find one option called Input Controllers; select it. To the right, you’ll see a couple of new columns.

Next, double click on “Main Mouse Wheel” in the far-left column. This will display the “Configure Input Controller” window. D

Now, double-click on the first item labeled; “Scroll Up” to bring up the Select Controller Event Action. This is where you’ll define how your brush reacts to your mouse wheel.

In the Search input box, type out “context-brush-radius-increase-skip” and select it. This is the code to make your paintbrush larger. Click OK.

To adjust your brush smaller:

  1. Locate “Scroll Down” and double-click it.
  2. Type in the following and hit OK; “context-brush-radius-decrease-skip.”
  3. Hit Close and Ok to get out of the Preferences dialogue window.

Next up, try it out! Move your mouse wheel button up and down to adjust the brush.

What’s Next?

Now that you know three different ways to adjust your paintbrush size, which is your favorite method? Post it in the comments!

Want to learn more about brushes for GIMP?

Looking for the friendliest (private) Facebook group this side of the moon? Awesome! It’s a great place to share, learn, and master GIMP.

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