Conversion Form

MM
REM

About the Unit

Millimeter (mm): The millimeter (mm) is a physical unit of measurement, 1/10th of a centimeter. Like cm, mm is commonly used in graphic design and printing, where precise physical measurements are needed. In CSS, mm is useful for defining width, height, and other dimensions of elements in layouts that will be printed or converted to other physical formats. Using mm is an effective way to ensure precise and consistent layout dimensions during the printing process. For digital designs, the mm unit may be less practical, as most web interfaces benefit more from relative units to ensure a more adaptive user experience. However, for technical documents or precision graphics, mm may be the best choice.

Pro Tip: mmrem

Convert mm to rem for scalable typography.

Quick Reference: Unit Conversion by Tens

MMREM
10mm0.393701rem
20mm0.787402rem
30mm1.181102rem
40mm1.574803rem
50mm1.968504rem
60mm2.362205rem
70mm2.755906rem
80mm3.149606rem
90mm3.543307rem
100mm3.937008rem
110mm4.330709rem
120mm4.724409rem
130mm5.11811rem
140mm5.511811rem
150mm5.905512rem
160mm6.299213rem
170mm6.692913rem
180mm7.086614rem
190mm7.480315rem
200mm7.874016rem
210mm8.267717rem
220mm8.661417rem
230mm9.055118rem
240mm9.448819rem
250mm9.84252rem

Live Unit Preview

See how different CSS units affect the size of the box below:

10px

10rem

10em

10%

10vw

10vh

Common Mistake

Be cautious when mixing mm and rem without testing on different screen sizes.

Real Code Example

/* Mobile-first card with mm → rem */
.card {
  padding: 0mm;     /* undefinedrem */
  font-size: 1.5rem;
  width: min(90vw, 40ch);
}
Unidade não encontrada.

Keyboard Shortcuts

  • Ctrl + C: Convert
  • Ctrl + I: Invert units
  • Esc: Reset values

More popular conversions