Source: https://tailwindcss.com/docs/flex-basis

v4.1

Flexbox & Grid
flex-basis

Flexbox & Grid

flex-basis

Utilities for controlling the initial size of flex items.

| Class | Styles | | --- | --- | | basis-<number> | flex-basis: calc(var(--spacing) * <number>); | | basis-<fraction> | flex-basis: calc(<fraction> * 100%); | | basis-full | flex-basis: 100%; | | basis-auto | flex-basis: auto; | | basis-3xs | flex-basis: var(--container-3xs); /* 16rem (256px) */ | | basis-2xs | flex-basis: var(--container-2xs); /* 18rem (288px) */ | | basis-xs | flex-basis: var(--container-xs); /* 20rem (320px) */ | | basis-sm | flex-basis: var(--container-sm); /* 24rem (384px) */ | | basis-md | flex-basis: var(--container-md); /* 28rem (448px) */ | | basis-lg | flex-basis: var(--container-lg); /* 32rem (512px) */ | | basis-xl | flex-basis: var(--container-xl); /* 36rem (576px) */ | | basis-2xl | flex-basis: var(--container-2xl); /* 42rem (672px) */ | | basis-3xl | flex-basis: var(--container-3xl); /* 48rem (768px) */ | | basis-4xl | flex-basis: var(--container-4xl); /* 56rem (896px) */ | | basis-5xl | flex-basis: var(--container-5xl); /* 64rem (1024px) */ | | basis-6xl | flex-basis: var(--container-6xl); /* 72rem (1152px) */ | | basis-7xl | flex-basis: var(--container-7xl); /* 80rem (1280px) */ | | basis-(<custom-property>) | flex-basis: var(<custom-property>); | | basis-[<value>] | flex-basis: <value>; |

Examples

Using the spacing scale

Use basis-<number> utilities like basis-64 and basis-128 to set the initial size of flex items based on the spacing scale:

<div class="flex flex-row">  <div class="basis-64">01</div>  <div class="basis-64">02</div>  <div class="basis-128">03</div></div>

Using the container scale

Use utilities like basis-xs and basis-sm to set the initial size of flex items based on the container scale:

<div class="flex flex-row">  <div class="basis-3xs">01</div>  <div class="basis-2xs">02</div>  <div class="basis-xs">03</div>  <div class="basis-sm">04</div></div>

Using percentages

Use basis-<fraction> utilities like basis-1/2 and basis-2/3 to set the initial size of flex items:

<div class="flex flex-row">  <div class="basis-1/3">01</div>  <div class="basis-2/3">02</div></div>

Using a custom value

Use the basis-[<value>] syntax to set the basis based on a completely custom value:

<div class="basis-[30vw] ...">  <!-- ... --></div>

For CSS variables, you can also use the basis-(<custom-property>) syntax:

<div class="basis-(--my-basis) ...">  <!-- ... --></div>

This is just a shorthand for basis-[var(<custom-property>)] that adds the var() function for you automatically.

Responsive design

Prefix a flex-basis utility with a breakpoint variant like md: to only apply the utility at medium screen sizes and above:

<div class="flex flex-row">  <div class="basis-1/4 md:basis-1/3">01</div>  <div class="basis-1/4 md:basis-1/3">02</div>  <div class="basis-1/2 md:basis-1/3">03</div></div>

Learn more about using variants in the variants documentation .

Customizing your theme

Use the --container-* theme variables to customize the fixed-width basis utilities in your project:

@theme {  --container-4xs: 14rem; }

Now the basis-4xs utility can be used in your markup:

<div class="basis-4xs">  <!-- ... --></div>

The basis-<number> utilities are driven by the --spacing theme variable, which you can also customize:

@theme {  --spacing: 1px; }

Learn more about customizing the spacing scale in the theme documentation .

📄 tailwindcss/docs/flex-basis