Question

Utilities for controlling the initial size of flex items.

Quick reference

Class	Properties
basis-0	flex-basis: 0px;
basis-1	flex-basis: 0.25rem; /* 4px */
basis-2	flex-basis: 0.5rem; /* 8px */
basis-3	flex-basis: 0.75rem; /* 12px */
basis-4	flex-basis: 1rem; /* 16px */
basis-5	flex-basis: 1.25rem; /* 20px */
basis-6	flex-basis: 1.5rem; /* 24px */
basis-7	flex-basis: 1.75rem; /* 28px */
basis-8	flex-basis: 2rem; /* 32px */
basis-9	flex-basis: 2.25rem; /* 36px */
basis-10	flex-basis: 2.5rem; /* 40px */
basis-11	flex-basis: 2.75rem; /* 44px */
basis-12	flex-basis: 3rem; /* 48px */
basis-14	flex-basis: 3.5rem; /* 56px */
basis-16	flex-basis: 4rem; /* 64px */
basis-20	flex-basis: 5rem; /* 80px */
basis-24	flex-basis: 6rem; /* 96px */
basis-28	flex-basis: 7rem; /* 112px */
basis-32	flex-basis: 8rem; /* 128px */
basis-36	flex-basis: 9rem; /* 144px */
basis-40	flex-basis: 10rem; /* 160px */
basis-44	flex-basis: 11rem; /* 176px */
basis-48	flex-basis: 12rem; /* 192px */
basis-52	flex-basis: 13rem; /* 208px */
basis-56	flex-basis: 14rem; /* 224px */
basis-60	flex-basis: 15rem; /* 240px */
basis-64	flex-basis: 16rem; /* 256px */
basis-72	flex-basis: 18rem; /* 288px */
basis-80	flex-basis: 20rem; /* 320px */
basis-96	flex-basis: 24rem; /* 384px */
basis-auto	flex-basis: auto;
basis-px	flex-basis: 1px;
basis-0.5	flex-basis: 0.125rem; /* 2px */
basis-1.5	flex-basis: 0.375rem; /* 6px */
basis-2.5	flex-basis: 0.625rem; /* 10px */
basis-3.5	flex-basis: 0.875rem; /* 14px */
basis-1/2	flex-basis: 50%;
basis-1/3	flex-basis: 33.333333%;
basis-2/3	flex-basis: 66.666667%;
basis-1/4	flex-basis: 25%;
basis-2/4	flex-basis: 50%;
basis-3/4	flex-basis: 75%;
basis-1/5	flex-basis: 20%;
basis-2/5	flex-basis: 40%;
basis-3/5	flex-basis: 60%;
basis-4/5	flex-basis: 80%;
basis-1/6	flex-basis: 16.666667%;
basis-2/6	flex-basis: 33.333333%;
basis-3/6	flex-basis: 50%;
basis-4/6	flex-basis: 66.666667%;
basis-5/6	flex-basis: 83.333333%;
basis-1/12	flex-basis: 8.333333%;
basis-2/12	flex-basis: 16.666667%;
basis-3/12	flex-basis: 25%;
basis-4/12	flex-basis: 33.333333%;
basis-5/12	flex-basis: 41.666667%;
basis-6/12	flex-basis: 50%;
basis-7/12	flex-basis: 58.333333%;
basis-8/12	flex-basis: 66.666667%;
basis-9/12	flex-basis: 75%;
basis-10/12	flex-basis: 83.333333%;
basis-11/12	flex-basis: 91.666667%;
basis-full	flex-basis: 100%;

Basic usage

Setting the flex basis

Use the basis-* utilities to set the initial size of flex items.

01 02 03

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

---

Applying conditionally

Hover, focus, and other states

Tailwind lets you conditionally apply utility classes in different states using variant modifiers. For example, use hover:basis-1/2 to only apply the basis-1/2 utility on hover.

<div class="basis-1/3 hover:basis-1/2">
  <!-- ... -->
</div>

For a complete list of all available state modifiers, check out the Hover, Focus, & Other States documentation.

Breakpoints and media queries

You can also use variant modifiers to target media queries like responsive breakpoints, dark mode, prefers-reduced-motion, and more. For example, use md:basis-1/3 to apply the basis-1/3 utility at only 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>

To learn more, check out the documentation on Responsive Design, Dark Mode and other media query modifiers.

---

Using custom values

Customizing your theme

The default flex basis scale is a combination of the default spacing scale as well as a set of percentage based values.

You can customize your spacing scale by editing theme.spacing or theme.extend.spacing in your tailwind.config.js file.

tailwind.config.js

module.exports = {
  theme: {
    extend: {
      spacing: {
        '112': '28rem',
        '128': '32rem',
      }
    }
  }
}

Alternatively, you can customize just the flex basis scale by editing theme.flexBasis or theme.extend.flexBasis in your tailwind.config.js file.

tailwind.config.js

module.exports = {
  theme: {
    extend: {
      flexBasis: {
        '1/7': '14.2857143%',
        '2/7': '28.5714286%',
        '3/7': '42.8571429%',
        '4/7': '57.1428571%',
        '5/7': '71.4285714%',
        '6/7': '85.7142857%',
      }
    }
  }
}

Learn more about customizing the default theme in the theme customization documentation.

Arbitrary values

If you need to use a one-off flex-basis value that doesn’t make sense to include in your theme, use square brackets to generate a property on the fly using any arbitrary value.

<div class="basis-[14.2857143%]">
  <!-- ... -->
</div>

Learn more about arbitrary value support in the arbitrary values documentation.