block-size
block-size is a CSS property in the Size category. Controls element dimensions and intrinsic sizing behavior. The syntax is block-size: <length> | auto | max-content | min-content. A typical example: block-size: 200px; It is commonly applied to markup such as <div class="demo">Sample</div> Browser support: Chrome 1+, Firefox 1+, Safari 1+, Edge 12+. A close relative is box-sizing, which controls element dimensions and intrinsic sizing behavior. A close relative is contain-intrinsic-size, which controls element dimensions and intrinsic sizing behavior. A close relative is inline-size, which controls element dimensions and intrinsic sizing behavior. More about this category: CSS sizing properties for width, height, min/max dimensions. Related Size entries: box-sizing, contain-intrinsic-size, inline-size, interpolate-size, min-block-size, max-block-size, min-inline-size, max-inline-size. This page is part of the free CSS Reference documentation covering 841+ properties, selectors, functions, and at-rules, each with syntax, values, examples, and browser support.