<objective> Complete reference for Tailwind CSS v4.3 spacing utilities: margin (`m-*` and per-side variants, negative margins, `m-auto` centering), padding (`p-*` and per-side variants), logical block-axis margin/padding (`mbs-*`/`mbe-*`/`pbs-*`/`pbe-*`, since v4.2), and space-between (`space-x-*`/`space-y-*` for flex/grid children).

Documents the configurable spacing scale (--spacing base unit, default 0.25rem) and common composition patterns (centered containers, padded cards, stacked children). </objective>

Tailwind CSS Spacing Utilities

Complete reference for Tailwind CSS v4.3 spacing utilities: margin, padding, and space-between.

Quick Reference

Margin Classes

m-{size}: All sides margin
mx-{size}: Horizontal (left + right)
my-{size}: Vertical (top + bottom)
mt-{size}: Top margin
mr-{size}: Right margin
mb-{size}: Bottom margin
ml-{size}: Left margin
-m-{size}: Negative margin
m-auto: Auto margin (centering)

Padding Classes

p-{size}: All sides padding
px-{size}: Horizontal (left + right)
py-{size}: Vertical (top + bottom)
pt-{size}: Top padding
pr-{size}: Right padding
pb-{size}: Bottom padding
pl-{size}: Left padding

Logical Block-Axis Classes (since v4.2)

mbs-{size} / mbe-{size}: margin-block-start / margin-block-end
pbs-{size} / pbe-{size}: padding-block-start / padding-block-end
Inline-axis counterparts: ms-*/me-*, ps-*/pe-*

Space Between Children

space-x-{size}: Horizontal spacing between flex/grid children
space-y-{size}: Vertical spacing between flex/grid children

Spacing Scale

Tailwind CSS v4.3 uses a configurable spacing scale where --spacing is the base unit (default: 0.25rem/4px). Since v4.3.1, *-0 emits 0 and *-1 emits var(--spacing) instead of a calc().

| Class | Value | |-------|-------| | 0 | 0 | | px | 1px | | 0.5 | calc(var(--spacing) * 0.5) = 0.125rem | | 1 | var(--spacing) = 0.25rem | | 2 | calc(var(--spacing) * 2) = 0.5rem | | 3 | calc(var(--spacing) * 3) = 0.75rem | | 4 | calc(var(--spacing) * 4) = 1rem | | 6 | calc(var(--spacing) * 6) = 1.5rem | | 8 | calc(var(--spacing) * 8) = 2rem | | 12 | calc(var(--spacing) * 12) = 3rem | | 16 | calc(var(--spacing) * 16) = 4rem |

Common Patterns

Centered Container

<div class="mx-auto">Centered content</div>

Card with Padding

<div class="p-6 bg-white rounded-lg shadow">Card content</div>

Flex Items with Spacing

<div class="flex space-x-4">
  <div>Item 1</div>
  <div>Item 2</div>
  <div>Item 3</div>
</div>

Stack with Vertical Spacing

<div class="space-y-4">
  <p>Paragraph 1</p>
  <p>Paragraph 2</p>
  <p>Paragraph 3</p>
</div>

See detailed references: