This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The non-standard -moz-float-edge CSS property specifies whether the height and width properties of the element include the margin, border, or padding thickness.

/* Keyword values */
-moz-float-edge: border-box;
-moz-float-edge: content-box;
-moz-float-edge: margin-box;
-moz-float-edge: padding-box;

/* Global values */
-moz-float-edge: inherit;
-moz-float-edge: initial;
-moz-float-edge: unset;
Initial value content-box
Applies to all elements
Inherited no
Media visual
Computed value as specified
Animation type discrete
Canonical order the unique non-ambiguous order defined by the formal grammar



The height and width properties include the content, padding and border but not the margin.
The height and width properties include the content, but not the padding, border or margin.
The height and width properties include the content, padding, border and margin.
The height and width properties include the content and padding but not the border or margin.

Formal syntax

border-box | content-box | margin-box | padding-box


HTML Content

<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p></div>

CSS Content

.box {
  display: block;
  height: 5px;
  margin: 0.5em auto 0.5em auto;
  color: gray;
  -moz-float-edge: margin-box;
  box-sizing: border-box;


See also

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