calc() as CSS unit value

- CR

Method of allowing calculated values for length units, i.e. width: calc(100% - 3em)

IE

  1. 5.5 - 8
  2. 9
  3. 10
  4. 11

Edge

  1. 12 - 81
  2. 83

Firefox

  1. 2 - 3.6
  2. 4 - 15
  3. 16 - 77
  4. 78
  5. 79 - 80

Chrome

  1. 4 - 18
  2. 19 - 25
  3. 26 - 81
  4. 83
  5. 84 - 86

Safari

  1. 3.1 - 5.1
  2. 6
  3. 6.1 - 13
  4. 13.1
  5. 14 - TP

Opera

  1. 9 - 12.1
  2. 15 - 68
  3. 69

iOS Safari

  1. 3.2 - 5.1
  2. 6
  3. 7 - 13.3
  4. 13.4
  5. 14.0

Opera Mini

  1. all

Android Browser

  1. 2.1 - 4.3
  2. 4.4 - 4.4.4
  3. 81

Blackberry Browser

  1. 7
  2. 10

Opera Mobile

  1. 10 - 12.1
  2. 46

Chrome for Android

  1. 81

Firefox for Android

  1. 68

IE Mobile

  1. 10
  2. 11

UC Browser for Android

  1. 12.12

Samsung Internet

  1. 4 - 11.2
  2. 12.0

QQ Browser

  1. 10.4

Baidu Browser

  1. 7.12

KaiOS Browser

  1. 2.5

Support can be somewhat emulated in older versions of IE using the non-standard expression() syntax.

Due to the way browsers handle sub-pixel rounding differently, layouts using calc() expressions may have unexpected results.

Resources:
MDN Web Docs - calc
Mozilla Hacks article
WebPlatform Docs