How to use calc() with Tailwind CSS

February 17, 2022

Now with Tailwind CSS v3.0 and above, you can use arbitrary CSS statements in your classes, and they’ll get generated using the JIT (Just-In-Time) engine.

That means you can use a CSS calc() statement within a class, just by wrapping it inside square brackets.

The only caveat is that CSS classes can’t contain spaces. That means that you’ll just have to leave out the spaces you might normally write in a calc statement, for example the spaces in “calc(100 - 36px)”. Alternatively, you can replace the spaces with underscores (_), which Tailwind CSS will interpret as spaces.

Here’s an example of the two ways to use the calc() CSS function with Tailwind:

<div class="bg-red-500 w-24 h-[calc(100vh-36px)]"></div>
<div class="bg-red-500 w-24 h-[calc(100vh_-_36px)]"></div>