CSS3 Box-sizing

Method of specifying whether or not an element's borders and padding should be included in size units

Spec	https://www.w3.org/TR/css-sizing/#box-sizing
Status	W3C Working Draft

IE	Edge	Firefox	Chrome	Safari	Opera
			98
		95	97
		94	96	TP
11	95	93	95	15	80
10	94	92	94	14.1	79
9	93	91	93	14	78
8	92	90	92	13.1	77
Show all
7	91	89	91	13	76
6	90	88	90	12.1	75
5.5	89	87	89	12	74
	88	86	88	11.1	73
	87	85	87	11	72
	86	84	86	10.1	71
	85	83	85	10	70
	84	82	84	9.1	69
	83	81	83	9	68
	81	80	81	8	67
	80	79	80	7.1	66
	79	78	79	7	65
	18	77	78	6.1	64
	17	76	77	6	63
	16	75	76	5.1	62
	15	74	75	5 (*)	60
	14	73	74	4 (*)	58
	13	72	73	3.2 (*)	57
	12	71	72	3.1 (*)	56
		70	71		55
		69	70		54
		68	69		53
		67	68		52
		66	67		51
		65	66		50
		64	65		49
		63	64		48
		62	63		47
		61	62		46
		60	61		45
		59	60		44
		58	59		43
		57	58		42
		56	57		41
		55	56		40
		54	55		39
		53	54		38
		52	53		37
		51	52		36
		50	51		35
		49	50		34
		48	49		33
		47	48		32
		46	47		31
		45	46		30
		44	45		29
		43	44		28
		42	43		27
		41	42		26
		40	41		25
		39	40		24
		38	39		23
		37	38		22
		36	37		21
		35	36		20
		34	35		19
		33	34		18
		32	33		17
		31	32		16
		30	31		15
		29	30		12.1
		28 (*)	29		12
		27 (*)	28		11.6
		26 (*)	27		11.5
		25 (*)	26		11.1
		24 (*)	25		11
		23 (*)	24		10.6
		22 (*)	23		10.5
		21 (*)	22		10.0-10.1
		20 (*)	21		9.5-9.6
		19 (*)	20		9
		18 (*)	19
		17 (*)	18
		16 (*)	17
		15 (*)	16
		14 (*)	15
		13 (*)	14
		12 (*)	13
		11 (*)	12
		10 (*)	11
		9 (*)	10
		8 (*)	9 (*)
		7 (*)	8 (*)
		6 (*)	7 (*)
		5 (*)	6 (*)
		4 (*)	5 (*)
		3.6 (*)	4 (*)
		3.5 (*)
		3 (*)
		2 (*)

Safari on iOS	Opera Mini	Android Browser	Blackberry Browser	Opera Mobile	Android Chrome	Android Firefox	IE Mobile	Android UC Browser	Samsung Internet	QQ Browser	Baidu Browser	KaiOS Browser
15	all	94	10	64	94	92	11	12.12	15.0	10.4	7.12	2.5
14.5-14.8		4.4.3-4.4.4	7 (*)	12.1			10		14.0
14.0-14.4		4.4		12					13.0
13.4-13.7		4.2-4.3		11.5					12.0
Show all
13.3		4.1		11.1					11.1-11.2
13.2		4		11					10.1
13.0-13.1		3 (*)		10					9.2
12.2-12.5		2.3 (*)							8.2
12.0-12.1		2.2 (*)							7.2-7.4
11.3-11.4		2.1 (*)							6.2-6.4
11.0-11.2									5.0-5.4
10.3									4
10.0-10.2
9.3
9.0-9.2
8.1-8.4
8
7.0-7.1
6.0-6.1
5.0-5.1
4.2-4.3 (*)
4.0-4.1 (*)
3.2 (*)

Notes

Firefox versions before 57 also supported the padding-box value for box-sizing, though this value was been removed from the specification and later versions of the browser.

^* Partial support with prefix.

Bugs

• Android browsers do not calculate correctly the dimensions (width and height) of the HTML select element.

• Safari 6.0.x does not use box-sizing on elements with display: table;

• IE9 will subtract the width of the scrollbar to the width of the element when set to position: absolute / fixed , overflow: auto / overflow-y: scroll

• IE 8 ignores box-sizing: border-box if min/max-width/height is used.

• Chrome has problems selecting options from the select element when using box-sizing: border-box and browser zoom level is less than 100%.

• In IE8, the min-width property applies to content-box even if box-sizing is set to border-box.

• In Chrome, the inherit value doesn't work on elements inside details, this could lead to unexpected behaviour when box-sizing: inherit is used in an universal selector, see https://bugs.chromium.org/p/chromium/issues/detail?id=589475

Resources

• MDN Web Docs - CSS box-sizing
• Blog post
• Polyfill for IE
• CSS Tricks
• WebPlatform Docs