How to calculate rem?

Question

css

Good afternoon. Decided to use rem in a new project. As you know, I set html{ font-size : 16px}
And now one rem = 16px, 32px = 2 rem. However, for example, I have 24px in Photoshop. To do this, I need to constantly calculate 24/16 = 1.5rem with a calculator. It is not always convenient to sit next to a calculator. However, I'm using STYLUs and there are mixins, functions, etc. It's possible to create auto mixins. calculations and converting px to rem

Answer 1

Google
first link in google

Answer 2

html{font-size : 10px}
and it will be easy to count