# CSS Units Question

**URL:** <https://forum.kirupa.com/t/css-units-question/306454>\
**Category:** web dev\
**Created:** [March 15, 2010, 9:34pm UTC](https://forum.kirupa.com/t/css-units-question/306454 "2010-03-15T21:34:12Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![nvidia](https://avatars.discourse-cdn.com/v4/letter/n/bc8723/32.png) [@nvidia](https://forum.kirupa.com/u/nvidia)\
**Post date:** [March 15, 2010, 9:34pm UTC](https://forum.kirupa.com/t/css-units-question/306454/1 "2010-03-15T21:34:12Z")

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Hi,

i’ve been going through the css tutorial over the W3Schools website, and i just wanted to ask you guys, are there any guidlines/websites that you can suggest to me that exaplain when to use CSS units e.g % or PX? because if i want to create a series of boxes of different shapes, how do i know which measurement would be of ‘best practice’?

Thanks