REM to MM Converter

Use this free online rem to mm converter tool to convert root em units to millimeters. Millimeters are an absolute unit used for precise print measurements. This converter helps translate web typography to precise metric dimensions.

To convert rem to millimeters, multiply the rem value by the root font-size to get pixels, then multiply by 25.4 and divide by 96. The default root font-size is 16px. This provides precise metric measurements for print.

Conversion Formula

mm = (rem × root font-size × 25.4) ÷ 96

For example, to convert 6rem to mm with 16px root font-size, calculate (6 × 16 × 25.4) ÷ 96 = 25.4mm. Similarly, 3rem approximately equals 12.7mm because (3 × 16 × 25.4) ÷ 96 ≈ 12.7.

REM to MM Converter Conversion Table (Root: 16px)

REMMM
0.0625rem0.2646mm
0.25rem1.058mm
0.5rem2.117mm
0.75rem3.175mm
1rem4.233mm
1.25rem5.292mm
1.5rem6.35mm
2rem8.467mm
2.5rem10.58mm
3rem12.7mm
4rem16.93mm
6rem25.4mm
8rem33.87mm
10rem42.33mm
11rem46.57mm
12rem50.8mm
13rem55.03mm
14rem59.27mm
16rem67.73mm
20rem84.67mm
30rem127mm
36rem152mm
48rem203mm
50rem212mm
60rem254mm
62rem262mm
64rem271mm
70rem296mm
75rem318mm
80rem339mm
90rem381mm
100rem423mm
120rem508mm

What is REM?

REM (Root EM) is a relative CSS unit based on the root element's font size, typically 16px by default in most browsers. Unlike EM units which cascade based on parent elements, REM provides consistent sizing throughout the document. This makes REM ideal for creating scalable, accessible designs that respect user font-size preferences.

What is MM?

Millimeters (mm) are an absolute CSS unit representing physical millimeters, primarily used for precise print measurements. In web contexts, 1mm equals approximately 3.78 pixels. Millimeters are most useful in print stylesheets and international design contexts where metric precision is required.

W3Schools - CSS UnitsMDN - CSS Length ValuesPrint CSS Guide

Related Converters

REM to PXREM to EMREM to VWREM to VHREM to PTREM to INREM to PCREM to CMMM to REM