CSS max-block-size Property Reference

The CSS max-block-size property is a standard property in CSS Logical Properties and Values. Review its formal syntax, computed behavior, and practical declarations.

Updated 2026-08-12

max-block-size overview

The CSS max-block-size property is a standard property in CSS Logical Properties and Values. Review its formal syntax, computed behavior, and practical declarations.

The property is not inherited by default. Use an explicit global keyword when inheritance is intended.

Syntax and formal definition

max-block-size formal syntax

Field	Value
Formal syntax	<'max-width'>
Initial value	none
Applies to	sameAsWidthAndHeight
Inherited	No
Percentages	blockSizeOfContainingBlock
Computed value	sameAsMaxWidthAndMaxHeight
Animation type	lpc
Media	visual
Specification group	CSS Logical Properties and Values
Status	Standard

Practical examples

These declarations demonstrate valid ways to set max-block-size. The initial and inherit global keywords remain available even when a property-specific value is preferable.

max-block-size live example

CSS

.reset-example {
  max-block-size: initial;
}

.inherit-example {
  max-block-size: inherit;
}

@supports (max-block-size: initial) {
  .supported {
    max-block-size: initial;
  }
}