---
title: Units
order: 40
---

Internally, freesewing uses millimeter. 
When you write `1`, that’s one mm. When you write `7.8`, that’s 7.8mm.

While you can use cm or inch on the FreeSewing website, that is merely a layer of 
abstration on top of the internal units, which are always mm.

So as a pattern designer, you will work with mm.