Changing the code font size in WebStorm IDE

I can't seem to find a way to change the code font size in WebStorm. I change the font size in options and it changes the menu and toolbar font size but not the actual code. Any ideas?

Settings (Preferences on Mac) | Editor | Colors & Fonts | Font, Size:

Before you can change this setting you must click "Save As..." and save the scheme under a custom name.

If you came here because you already found that screen, but the text box was locked...

This is because you cannot modify the current theme.

Click "Save As..." to save a copy of your current theme, now you should be able to edit whatever you want.

There is also an option to enable mouse wheel zooming, like in browsers:

File > Settings > Editor > Change font size with Ctrl+Mouse Wheel.

If you are a new WebStorm 10.0.4 user,

File > Settings > Editor > General > Change font size with Ctrl+Mouse Wheel.

The answer that discusses how to dynamically change the font size via the mouse wheel is partially correct, but leaves out a crucial step:

1. File
2. Settings
3. Editor
4. General (this is the crucial step missing from the previous answer)
5. Set the "Change font size (Zoom) with Ctrl+M

The previous answer was missing the crucial step 4, which, when omitted, leaves you wondering where the magic checkbox control is located.