<strong>Experimental:</strong> <strong>This is an <a href="/en-US/docs/MDN/Guidelines/Conventionsdefinitions#experimental">experimental technology</a></strong><br>Check the <a href="#browsercompatibility">Browser compatibility table</a> carefully before using this in production.

90% Positive percentage +90% Positive percentage with leading + -90% Negative percentage — not valid for all properties that use percentages 

<frequency-percentage>

Experimental: This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The <frequency-percentage> CSS data type represents a value that can be either a <frequency> or a <percentage>. Frequency values, e.g. the pitch of a speaking voice, are not currently used in any CSS properties.

Syntax

The value of a <frequency-percentage> is either a <frequency> or a <percentage>; see their individual reference pages for details about their syntaxes.

Description

Use in calc()

Where a <frequency-percentage> is specified as an allowable type, this means that the percentage resolves to a frequency and therefore can be used in a calc() expression.

Examples

Valid percentage values

90% Positive percentage +90% Positive percentage with leading + -90% Negative percentage — not valid for all properties that use percentages 

Invalid percentage values

90 % No space is allowed between the number and the unit 

Valid frequency values

12Hz     Positive integer 4.3Hz    Non-integer 14KhZ    The unit is case-insensitive, though non-SI capitalization is not recommended. +0Hz     Zero, with a leading + and a unit -0kHz    Zero, with a leading - and a unit 

Invalid frequency values

12.0     This is a <number>, not an <frequency>, because it is missing a unit. 7 Hz     No space is allowed between the number and the unit. 0        Although unitless zero is an allowable <length>, it's an invalid <frequency>. 

Specifications

See also

Last modified: Nov 21, 2021, by MDN contributors