CSS3 Click Chart | CSS3 Browser Support and Information

Values Using `calc()`

Allows you to use a function in place of a length value to calculate the size or shape of an element instead of defining it explicitly.

.element {
    width: -webkit-calc(100% + 20px);
    width: -moz-calc(100% + 20px);
    width: calc(100% + 20px);
}

The width of this element is 70% minus 50px, using the calc() function.

Standard Syntax:
IE9+, Firefox 16+

Vendor Prefix:
Firefox 4+, Chrome 19+, Safari 6+