diff --git a/CHANGELOG.md b/CHANGELOG.md
index b6e8e5b878f8..d0276e2786b9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Support bare spacing values for `auto-rows-*` and `auto-cols-*` utilities (e.g. `auto-rows-12` and `auto-cols-16`) ([#20229](https://github.com/tailwindlabs/tailwindcss/pull/20229))
+
 ### Fixed
 
 - Ensure `@tailwindcss/cli` in `--watch` mode doesn't crash on Windows when `@source` points to a directory that doesn't exist ([#20242](https://github.com/tailwindlabs/tailwindcss/pull/20242))
diff --git a/packages/tailwindcss/src/utilities.test.ts b/packages/tailwindcss/src/utilities.test.ts
index 3adabd010523..0cf35bd2ff60 100644
--- a/packages/tailwindcss/src/utilities.test.ts
+++ b/packages/tailwindcss/src/utilities.test.ts
@@ -9012,15 +9012,28 @@ test('break-after', async () => {
 
 test('auto-cols', async () => {
   expect(
-    await run([
-      'auto-cols-auto',
-      'auto-cols-min',
-      'auto-cols-max',
-      'auto-cols-fr',
-      'auto-cols-[2fr]',
-    ]),
+    await run(
+      [
+        'auto-cols-auto',
+        'auto-cols-min',
+        'auto-cols-max',
+        'auto-cols-fr',
+        'auto-cols-[2fr]',
+        'auto-cols-12',
+      ],
+      css`
+        @tailwind utilities;
+        @theme {
+          --spacing: 0.25rem;
+        }
+      `,
+    ),
   ).toMatchInlineSnapshot(`
     "
+    .auto-cols-12 {
+      grid-auto-columns: calc(var(--spacing) * 12);
+    }
+
     .auto-cols-\\[2fr\\] {
       grid-auto-columns: 2fr;
     }
@@ -9040,6 +9053,10 @@ test('auto-cols', async () => {
     .auto-cols-min {
       grid-auto-columns: min-content;
     }
+
+    :root, :host {
+      --spacing: .25rem;
+    }
     "
   `)
   expect(
@@ -9129,15 +9146,28 @@ test('grid-flow', async () => {
 
 test('auto-rows', async () => {
   expect(
-    await run([
-      'auto-rows-auto',
-      'auto-rows-min',
-      'auto-rows-max',
-      'auto-rows-fr',
-      'auto-rows-[2fr]',
-    ]),
+    await run(
+      [
+        'auto-rows-auto',
+        'auto-rows-min',
+        'auto-rows-max',
+        'auto-rows-fr',
+        'auto-rows-[2fr]',
+        'auto-rows-12',
+      ],
+      css`
+        @tailwind utilities;
+        @theme {
+          --spacing: 0.25rem;
+        }
+      `,
+    ),
   ).toMatchInlineSnapshot(`
     "
+    .auto-rows-12 {
+      grid-auto-rows: calc(var(--spacing) * 12);
+    }
+
     .auto-rows-\\[2fr\\] {
       grid-auto-rows: 2fr;
     }
@@ -9157,6 +9187,10 @@ test('auto-rows', async () => {
     .auto-rows-min {
       grid-auto-rows: min-content;
     }
+
+    :root, :host {
+      --spacing: .25rem;
+    }
     "
   `)
   expect(
diff --git a/packages/tailwindcss/src/utilities.ts b/packages/tailwindcss/src/utilities.ts
index ba7b9a39d88e..ae52159d320b 100644
--- a/packages/tailwindcss/src/utilities.ts
+++ b/packages/tailwindcss/src/utilities.ts
@@ -1985,6 +1985,11 @@ export function createUtilities(theme: Theme) {
 
   functionalUtility('auto-cols', {
     themeKeys: ['--grid-auto-columns'],
+    handleBareValue: ({ value }) => {
+      if (!theme.resolve(null, ['--spacing'])) return null
+      if (!isValidSpacingMultiplier(value)) return null
+      return `--spacing(${value})`
+    },
     handle: (value) => [decl('grid-auto-columns', value)],
     staticValues: {
       auto: [decl('grid-auto-columns', 'auto')],
@@ -1996,6 +2001,11 @@ export function createUtilities(theme: Theme) {
 
   functionalUtility('auto-rows', {
     themeKeys: ['--grid-auto-rows'],
+    handleBareValue: ({ value }) => {
+      if (!theme.resolve(null, ['--spacing'])) return null
+      if (!isValidSpacingMultiplier(value)) return null
+      return `--spacing(${value})`
+    },
     handle: (value) => [decl('grid-auto-rows', value)],
     staticValues: {
       auto: [decl('grid-auto-rows', 'auto')],