flex-basis

Utilities for controlling the initial size of flex items.

Quick reference

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>;

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

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:

<!-- [!code classes:basis-64,basis-128] -->
<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:

<!-- [!code classes:basis-3xs,basis-2xs,basis-xs,basis-sm] -->
<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:

<!-- [!code classes:basis-1/3,basis-2/3] -->
<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.