CSS numeric factory functions

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.

* Some parts of this feature may have varying levels of support.

The CSS numeric factory functions, such as CSS.em() and CSS.turn() are methods that return CSSUnitValues with the value being the numeric argument and the unit being the name of the method used. These functions create new numeric values less verbosely than using the CSSUnitValue() constructor.

Syntax

js
CSS.number(number)
CSS.percent(number)

// <length>
CSS.em(number)
CSS.ex(number)
CSS.ch(number)
CSS.ic(number)
CSS.rem(number)
CSS.lh(number)
CSS.rlh(number)
CSS.vw(number)
CSS.vh(number)
CSS.vi(number)
CSS.vb(number)
CSS.vmin(number)
CSS.vmax(number)
CSS.cm(number)
CSS.mm(number)
CSS.Q(number)
CSS.in(number)
CSS.pt(number)
CSS.pc(number)
CSS.px(number)

// <angle>
CSS.deg(number)
CSS.grad(number)
CSS.rad(number)
CSS.turn(number)

// <time>
CSS.s(number)
CSS.ms(number)

// <frequency>
CSS.Hz(number)
CSS.kHz(number)

// <resolution>
CSS.dpi(number)
CSS.dpcm(number)
CSS.dppx(number)

// <flex>
CSS.fr(number)

Examples

We use the CSS.vmax() numeric factory function to create a CSSUnitValue:

js
const height = CSS.vmax(50);

console.log(height); // CSSUnitValue {value: 50, unit: "vmax"}
console.log(height.value); // 50
console.log(height.unit); // vmax

In this example, we set the margin on our element using the CSS.px() factory function:

js
myElement.attributeStyleMap.set("margin", CSS.px(40));
const currentMargin = myElement.attributeStyleMap.get("margin");
console.log(currentMargin.value, currentMargin.unit); // 40, 'px'

Specifications

Specification
CSS Object Model (CSSOM)
# namespacedef-css

Browser compatibility

See also