Unitless number
A unitless number is a CSS numeric value written without a measurement unit and interpreted according to the receiving property.
CSS in Depth, Second Edition
A unitless number is a CSS numeric value written without a unit and interpreted according to the property that receives it.
- How it is used
- Uses unitless numbers for property-specific values and adaptable line-height, especially in inherited typography.
- How deep it goes
- Explains inheritance, local line-height calculation, zero-value limits, and a points-to-pixels conversion, stopping short of broader numeric CSS syntax.
- Examples
- Demonstrates body line-height, an enlarged paragraph, overlapping unit-based text, and conversion of 18pt leading to 1.5.
- What you can do after
- Apply unitless line-height and distinguish safe zero values from unsupported angular and time-based uses.
Read how CSS in Depth, Second Edition explains unitless number →
Math for Web Design
A unitless value is a CSS numeric value without a length or other measurement unit whose interpretation depends on the property.
- How it is used
- Preserves proportional line-height through inheritance and supplies unitless angle inputs to JavaScript trigonometric functions.
- How deep it goes
- Explains inheritance calculations, responsive formulas, and degree-radian conversion, stopping short of broader CSS numeric-value rules.
- Examples
- Uses inherited line-height examples, CSS typography calculations, a scaling results table, and JavaScript degree-radian formulas.
- What you can do after
- Apply unitless line-height for proportional inheritance and convert degree values to JavaScript-compatible radians.
Related concepts
- line-height propertyuses · The CSS line-height property specifies the height of each line box and thereby controls the vertical spacing of text lines.
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