Millimetres to Pixels


New Member
Hi Guys

I am converting mm to pixels using Indesign and Photoshop which both produce the same result, 12mm to 34px.

If I use an onLine converter I get a totally different result, 12mm to 45.4px.

Can anyone explain why and what is best to tell a client to go by for their Brand Guidelines?

I just specify in physical units such as mm or pts, since pixels are screen measurements and technically don't exist in physical space. Add into the mix retina devices where elements can be twice or three times as big and you've got a lot of confusion.