The calc function

The calc function allows you to calculate CSS property values. The function takes a mathematical expression as a parameter, the result of which can be used as the value of a CSS property. The expression may include the +, -, *, / operators.

Syntax

cssselector {
  property: calc(expression);
}

Example

Let's make the block width equal to 100% of the parent's width minus 50px:

html<div id="parent">
  <div id="child"></div>
</div>

css#child {
  width: calc(100% - 50px);
  height: 100px;
  margin: 0 auto;
  border: 1px solid red;
}
#parent {
  border: 1px solid green;
}

Результат:

See also