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<frequency-percentage>

The <frequency-percentage> CSS data type represents a value that can be either a {{Cssxref("frequency")}} or a {{Cssxref("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 {{Cssxref("frequency")}} or a {{Cssxref("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.

Formal syntax​

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​

Browser compatibility​

See also​