Ratio

The ratio helper keeps a box at a fixed aspect ratio whatever its width, which is perfect for media placeholders, thumbnails, galleries and banners. Pick ratio-1x1, ratio-4x3, ratio-16x9 or ratio-21x9, or set any ratio with the --ui-aspect-ratio variable.

1The four built-in ratios

ratio-1x1, ratio-4x3, ratio-16x9 and ratio-21x9 next to each other, filled with a plain div.

1:1

4:3

16:9

21:9

<div class="row g-3">
  <div class="col-6 col-md-3">
    <div class="ratio ratio-1x1">
      <div class="flex items-center justify-center bg-primary-subtle text-primary-emphasis border border-primary/30 rounded-md font-semibold">
        1:1
      </div>
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="ratio ratio-4x3">
      <div class="flex items-center justify-center bg-primary-subtle text-primary-emphasis border border-primary/30 rounded-md font-semibold">
        4:3
      </div>
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="ratio ratio-16x9">
      <div class="flex items-center justify-center bg-primary-subtle text-primary-emphasis border border-primary/30 rounded-md font-semibold">
        16:9
      </div>
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="ratio ratio-21x9">
      <div class="flex items-center justify-center bg-primary-subtle text-primary-emphasis border border-primary/30 rounded-md font-semibold">
        21:9
      </div>
    </div>
  </div>
</div>

2Video placeholder

A 16:9 poster image with a centred play button, ready for a video player of your choice.

<div class="ratio ratio-16x9 rounded-md overflow-hidden" style="max-width:36rem">
  <div>
    <img src="https://images.unsplash.com/photo-1753162658547-f017a4d84541?auto=format&fit=crop&w=1600&h=700&q=70" alt="Video poster" class="w-full h-full object-cover">
    <button type="button" class="btn btn-light rounded-full absolute top-1/2 start-1/2 -translate-x-1/2 -translate-y-1/2 shadow-md" aria-label="Play video"><i class="bi bi-play-fill" aria-hidden="true"></i></button>
  </div>
</div>

3Square product thumbnails

ratio-1x1 with object-fit-cover gives every product the same tile, whatever the photo size.

Design retainer

Packaging design

Social kit

Video edit

Print collateral

Website package

<div class="row g-2">
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-md overflow-hidden border">
      <img src="../assets/img/product-5.svg" alt="Design retainer" class="object-cover">
    </div>
    <p class="small truncate mt-1 mb-0">Design retainer</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-md overflow-hidden border">
      <img src="../assets/img/product-11.svg" alt="Packaging design" class="object-cover">
    </div>
    <p class="small truncate mt-1 mb-0">Packaging design</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-md overflow-hidden border">
      <img src="../assets/img/product-3.svg" alt="Social kit" class="object-cover">
    </div>
    <p class="small truncate mt-1 mb-0">Social kit</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-md overflow-hidden border">
      <img src="../assets/img/product-6.svg" alt="Video edit" class="object-cover">
    </div>
    <p class="small truncate mt-1 mb-0">Video edit</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-md overflow-hidden border">
      <img src="../assets/img/product-10.svg" alt="Print collateral" class="object-cover">
    </div>
    <p class="small truncate mt-1 mb-0">Print collateral</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-md overflow-hidden border">
      <img src="../assets/img/product-2.svg" alt="Website package" class="object-cover">
    </div>
    <p class="small truncate mt-1 mb-0">Website package</p>
  </div>
</div>

4Cinematic hero banner

ratio-21x9 for a wide banner with a headline overlay.

Digital products with personality

Every detail is handled by people who care about getting it right.

<div class="ratio ratio-21x9 rounded-lg overflow-hidden">
  <div>
    <img src="https://images.unsplash.com/photo-1752650736252-dff5244c8a7a?auto=format&fit=crop&w=1600&h=700&q=70" alt="" class="w-full h-full object-cover">
    <div class="absolute bottom-0 start-0 p-4 md:p-6 text-white" style="background:rgba(0,0,0,.45)">
      <h3 class="h4 mb-1">Digital products with personality</h3>
      <p class="small mb-0 hidden sm:block">Every detail is handled by people who care about getting it right.</p>
    </div>
  </div>
</div>

5Map placeholder

A 4:3 box reserved for a map, showing the address until the map loads.

Nimbus Kit30 Hillcrest Road, Vancouver

<div class="ratio ratio-4x3" style="max-width:24rem">
  <div class="flex flex-col items-center justify-center bg-surface-3 border rounded-md text-center p-4">
    <span class="text-4xl text-primary-ink"><i class="bi bi-geo-alt-fill" aria-hidden="true"></i></span><strong>Nimbus Kit</strong><span class="small text-muted">30 Hillcrest Road, Vancouver</span>
  </div>
</div>

6Custom 3:2 photo

Any ratio works with the --ui-aspect-ratio variable: 2 / 3 = 66.67% for classic photo prints.

The small habits that make a big difference — 3:2 · Our favourite tips for busy weeks

<figure class="mb-0" style="max-width:28rem">
  <div class="ratio rounded-md overflow-hidden" style="--ui-aspect-ratio:66.67%">
    <img src="https://images.unsplash.com/photo-1777923311853-d14b7beb9fec?auto=format&fit=crop&w=1200&h=800&q=70" alt="The small habits that make a big difference" class="object-cover">
  </div>
  <figcaption class="small text-muted mt-1">3:2 &middot; Our favourite tips for busy weeks</figcaption>
</figure>

7Portrait team cards

A 3:4 portrait ratio (133.33%) for team photos in cards.

Finn Nguyen

Customer Success

Arjun Varga

Art Director

Sofia Harlow

Customer Success

<div class="row g-3">
  <div class="col-6 col-md-4">
    <div class="card h-full">
      <div class="ratio card-img-top overflow-hidden" style="--ui-aspect-ratio:133.33%">
        <img src="https://images.unsplash.com/photo-1753162658407-93888aaabfae?auto=format&fit=crop&w=1200&h=800&q=70" alt="Finn Nguyen" class="object-cover">
      </div>
      <div class="card-body py-2">
        <h3 class="h6 mb-0">Finn Nguyen</h3>
        <p class="small text-muted mb-0">Customer Success</p>
      </div>
    </div>
  </div>
  <div class="col-6 col-md-4">
    <div class="card h-full">
      <div class="ratio card-img-top overflow-hidden" style="--ui-aspect-ratio:133.33%">
        <img src="https://images.unsplash.com/photo-1777923311853-d14b7beb9fec?auto=format&fit=crop&w=1200&h=800&q=70" alt="Arjun Varga" class="object-cover">
      </div>
      <div class="card-body py-2">
        <h3 class="h6 mb-0">Arjun Varga</h3>
        <p class="small text-muted mb-0">Art Director</p>
      </div>
    </div>
  </div>
  <div class="col-6 col-md-4">
    <div class="card h-full">
      <div class="ratio card-img-top overflow-hidden" style="--ui-aspect-ratio:133.33%">
        <img src="https://images.unsplash.com/photo-1752650736252-dff5244c8a7a?auto=format&fit=crop&w=1200&h=800&q=70" alt="Sofia Harlow" class="object-cover">
      </div>
      <div class="card-body py-2">
        <h3 class="h6 mb-0">Sofia Harlow</h3>
        <p class="small text-muted mb-0">Customer Success</p>
      </div>
    </div>
  </div>
</div>

8Vertical stories

A 9:16 ratio (177.78%) for phone sized stories or short clips in a scrolling row.

Diego

Jonah

Isla

Mateo

<div class="flex gap-2 overflow-auto pb-1">
  <div class="shrink-0" style="width:7rem">
    <div class="ratio rounded-lg overflow-hidden" style="--ui-aspect-ratio:177.78%">
      <div>
        <img src="https://images.unsplash.com/photo-1742440710193-3547e0b9d4db?auto=format&fit=crop&w=1200&h=800&q=70" alt="Story by Diego Okafor" class="w-full h-full object-cover"><span class="absolute bottom-0 start-0 m-1 badge text-bg-dark">Diego</span>
      </div>
    </div>
  </div>
  <div class="shrink-0" style="width:7rem">
    <div class="ratio rounded-lg overflow-hidden" style="--ui-aspect-ratio:177.78%">
      <div>
        <img src="https://images.unsplash.com/photo-1752650736252-dff5244c8a7a?auto=format&fit=crop&w=1200&h=800&q=70" alt="Story by Jonah Kowalski" class="w-full h-full object-cover"><span class="absolute bottom-0 start-0 m-1 badge text-bg-dark">Jonah</span>
      </div>
    </div>
  </div>
  <div class="shrink-0" style="width:7rem">
    <div class="ratio rounded-lg overflow-hidden" style="--ui-aspect-ratio:177.78%">
      <div>
        <img src="https://images.unsplash.com/photo-1787647561978-df268f9e9ec2?auto=format&fit=crop&w=1200&h=800&q=70" alt="Story by Isla Alvarez" class="w-full h-full object-cover"><span class="absolute bottom-0 start-0 m-1 badge text-bg-dark">Isla</span>
      </div>
    </div>
  </div>
  <div class="shrink-0" style="width:7rem">
    <div class="ratio rounded-lg overflow-hidden" style="--ui-aspect-ratio:177.78%">
      <div>
        <img src="https://images.unsplash.com/photo-1753162658407-93888aaabfae?auto=format&fit=crop&w=1200&h=800&q=70" alt="Story by Mateo Moreau" class="w-full h-full object-cover"><span class="absolute bottom-0 start-0 m-1 badge text-bg-dark">Mateo</span>
      </div>
    </div>
  </div>
</div>

9Chart area

A 16:9 box that keeps a simple bar chart in proportion on every screen.

Monthly bookings

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

<div class="card" style="max-width:36rem">
  <div class="card-header small font-semibold">
    Monthly bookings
  </div>
  <div class="card-body">
    <div class="ratio ratio-16x9">
      <div class="flex items-end gap-2" role="img" aria-label="Bar chart of monthly bookings">
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:23%">
          </div>
          <span class="small text-muted">Jan</span>
        </div>
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:81%">
          </div>
          <span class="small text-muted">Feb</span>
        </div>
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:74%">
          </div>
          <span class="small text-muted">Mar</span>
        </div>
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:37%">
          </div>
          <span class="small text-muted">Apr</span>
        </div>
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:46%">
          </div>
          <span class="small text-muted">May</span>
        </div>
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:32%">
          </div>
          <span class="small text-muted">Jun</span>
        </div>
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:85%">
          </div>
          <span class="small text-muted">Jul</span>
        </div>
        <div class="flex-auto flex flex-col justify-end items-center h-full">
          <div class="w-full bg-primary rounded-t-md" style="height:61%">
          </div>
          <span class="small text-muted">Aug</span>
        </div>
      </div>
    </div>
  </div>
</div>

10Blog card cover

ratio-16x9 as a card image keeps every post card in a grid the same height.

update

A checklist for your next website launch

Apr 8, 2026

<div class="card" style="max-width:22rem">
  <div class="ratio ratio-16x9 card-img-top overflow-hidden">
    <img src="https://images.unsplash.com/photo-1752650736252-dff5244c8a7a?auto=format&fit=crop&w=1200&h=800&q=70" alt="Inside our design process" class="object-cover">
  </div>
  <div class="card-body">
    <span class="badge text-bg-light border mb-2">update</span>
    <h3 class="h6">A checklist for your next website launch</h3>
    <p class="small text-muted mb-0">Apr 8, 2026</p>
  </div>
</div>

11Caption over a gradient

A 4:3 image with a gradient overlay so white caption text stays readable.

MontrealContent strategy

<div class="ratio ratio-4x3 rounded-lg overflow-hidden" style="max-width:24rem">
  <div>
    <img src="https://images.unsplash.com/photo-1753162658407-93888aaabfae?auto=format&fit=crop&w=1200&h=800&q=70" alt="" class="w-full h-full object-cover">
    <div class="absolute bottom-0 w-full p-4 text-white" style="background:linear-gradient(transparent,rgba(0,0,0,.7))">
      <strong class="block">Montreal</strong><span class="small">Content strategy</span>
    </div>
  </div>
</div>

12Mixed ratio gallery

Combining 1:1, 4:3 and 16:9 tiles in one responsive grid.

<div class="row g-2">
  <div class="col-md-6">
    <div class="ratio ratio-4x3 rounded-md overflow-hidden">
      <img src="https://images.unsplash.com/photo-1752650736677-94fe8cdb9d5c?auto=format&fit=crop&w=1200&h=800&q=70" alt="Gallery photo 1" class="object-cover">
    </div>
  </div>
  <div class="col-md-6">
    <div class="row g-2">
      <div class="col-6">
        <div class="ratio ratio-1x1 rounded-md overflow-hidden">
          <img src="https://images.unsplash.com/photo-1742440710453-d5db3a357362?auto=format&fit=crop&w=800&h=800&q=70" alt="Gallery photo 2" class="object-cover">
        </div>
      </div>
      <div class="col-6">
        <div class="ratio ratio-1x1 rounded-md overflow-hidden">
          <img src="https://images.unsplash.com/photo-1753162657329-beced5a7f63f?auto=format&fit=crop&w=800&h=800&q=70" alt="Gallery photo 3" class="object-cover">
        </div>
      </div>
      <div class="col-12">
        <div class="ratio ratio-21x9 rounded-md overflow-hidden">
          <img src="https://images.unsplash.com/photo-1753162658407-93888aaabfae?auto=format&fit=crop&w=1600&h=700&q=70" alt="Gallery photo 4" class="object-cover">
        </div>
      </div>
    </div>
  </div>
</div>

13Thumbnails in table cells

A small ratio-1x1 box keeps order line images square inside a table.

Image	Item	Price
	Packaging design	$4,450
	Design retainer	$3,350
	Logo refresh	$2,800

<table class="table align-middle mb-0">
  <thead>
    <tr>
      <th scope="col"><span class="sr-only">Image</span></th>
      <th scope="col">Item</th>
      <th scope="col" class="text-end">Price</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td style="width:4rem"><div class="ratio ratio-1x1 rounded-md overflow-hidden"><img src="../assets/img/product-11.svg" alt="Packaging design" class="object-cover"></div></td>
      <td class="align-middle">Packaging design</td>
      <td class="align-middle text-end">$4,450</td>
    </tr>
    <tr>
      <td style="width:4rem"><div class="ratio ratio-1x1 rounded-md overflow-hidden"><img src="../assets/img/product-5.svg" alt="Design retainer" class="object-cover"></div></td>
      <td class="align-middle">Design retainer</td>
      <td class="align-middle text-end">$3,350</td>
    </tr>
    <tr>
      <td style="width:4rem"><div class="ratio ratio-1x1 rounded-md overflow-hidden"><img src="../assets/img/product-7.svg" alt="Logo refresh" class="object-cover"></div></td>
      <td class="align-middle">Logo refresh</td>
      <td class="align-middle text-end">$2,800</td>
    </tr>
  </tbody>
</table>

14Empty cover placeholder

A dashed 4:3 area that reserves space for an image that has not been chosen yet.

No cover image yet

<div class="ratio ratio-4x3" style="max-width:20rem">
  <div class="flex flex-col items-center justify-center border border-2 border-secondary/30 rounded-lg text-muted wt-border-dashed">
    <span class="text-3xl"><i class="bi bi-image-fill" aria-hidden="true"></i></span><span class="small">No cover image yet</span>
  </div>
</div>

15Colour swatches

Empty square ratios make perfect colour swatches for a style guide.

primary

secondary

success

info

warning

danger

<div class="row g-2">
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-lg bg-primary">
      <span class="sr-only">primary</span>
    </div>
    <p class="small text-center mt-1 mb-0">primary</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-lg bg-secondary">
      <span class="sr-only">secondary</span>
    </div>
    <p class="small text-center mt-1 mb-0">secondary</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-lg bg-success">
      <span class="sr-only">success</span>
    </div>
    <p class="small text-center mt-1 mb-0">success</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-lg bg-info">
      <span class="sr-only">info</span>
    </div>
    <p class="small text-center mt-1 mb-0">info</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-lg bg-warning">
      <span class="sr-only">warning</span>
    </div>
    <p class="small text-center mt-1 mb-0">warning</p>
  </div>
  <div class="col-4 col-md-2">
    <div class="ratio ratio-1x1 rounded-lg bg-danger">
      <span class="sr-only">danger</span>
    </div>
    <p class="small text-center mt-1 mb-0">danger</p>
  </div>
</div>

16Video thumbnails with badges

Duration and status badges positioned over 16:9 thumbnails.

13:25New

How we ran a rebrand in eight weeks

4:38

Why motion matters for modern brands

10:59

Designing packaging that survives the shelf

<div class="row g-3">
  <div class="col-md-4">
    <div class="ratio ratio-16x9 rounded-md overflow-hidden">
      <div>
        <img src="https://images.unsplash.com/photo-1787647559705-d2ad3322020e?auto=format&fit=crop&w=1200&h=800&q=70" alt="" class="w-full h-full object-cover"><span class="absolute bottom-0 end-0 m-2 badge text-bg-dark">13:25</span><span class="absolute top-0 start-0 m-2 badge text-bg-danger">New</span>
      </div>
    </div>
    <p class="small font-semibold mt-1 mb-0">How we ran a rebrand in eight weeks</p>
  </div>
  <div class="col-md-4">
    <div class="ratio ratio-16x9 rounded-md overflow-hidden">
      <div>
        <img src="https://images.unsplash.com/photo-1753162658547-f017a4d84541?auto=format&fit=crop&w=1200&h=800&q=70" alt="" class="w-full h-full object-cover"><span class="absolute bottom-0 end-0 m-2 badge text-bg-dark">4:38</span>
      </div>
    </div>
    <p class="small font-semibold mt-1 mb-0">Why motion matters for modern brands</p>
  </div>
  <div class="col-md-4">
    <div class="ratio ratio-16x9 rounded-md overflow-hidden">
      <div>
        <img src="https://images.unsplash.com/photo-1742440710193-3547e0b9d4db?auto=format&fit=crop&w=1200&h=800&q=70" alt="" class="w-full h-full object-cover"><span class="absolute bottom-0 end-0 m-2 badge text-bg-dark">10:59</span>
      </div>
    </div>
    <p class="small font-semibold mt-1 mb-0">Designing packaging that survives the shelf</p>
  </div>
</div>

17Media list

Fixed width 4:3 thumbnails beside article titles in a reading list.

Lessons from a year of client workshops
Mar 7, 2026 · 10 min read
Five website mistakes that cost you leads
Mar 27, 2026 · 8 min read
What makes a brand memorable
Oct 17, 2025 · 5 min read

<ul class="list-unstyled mb-0 vstack gap-4">
  <li class="flex gap-4"><div class="shrink-0" style="width:6rem"><div class="ratio ratio-4x3 rounded-md overflow-hidden"><img src="https://images.unsplash.com/photo-1787647561978-df268f9e9ec2?auto=format&fit=crop&w=1200&h=800&q=70" alt="" class="object-cover"></div></div><div><h3 class="h6 mb-1">Lessons from a year of client workshops</h3><p class="small text-muted mb-0">Mar 7, 2026 &middot; 10 min read</p></div></li>
  <li class="flex gap-4"><div class="shrink-0" style="width:6rem"><div class="ratio ratio-4x3 rounded-md overflow-hidden"><img src="https://images.unsplash.com/photo-1753162658407-93888aaabfae?auto=format&fit=crop&w=1200&h=800&q=70" alt="" class="object-cover"></div></div><div><h3 class="h6 mb-1">Five website mistakes that cost you leads</h3><p class="small text-muted mb-0">Mar 27, 2026 &middot; 8 min read</p></div></li>
  <li class="flex gap-4"><div class="shrink-0" style="width:6rem"><div class="ratio ratio-4x3 rounded-md overflow-hidden"><img src="https://images.unsplash.com/photo-1742440710453-d5db3a357362?auto=format&fit=crop&w=1200&h=800&q=70" alt="" class="object-cover"></div></div><div><h3 class="h6 mb-1">What makes a brand memorable</h3><p class="small text-muted mb-0">Oct 17, 2025 &middot; 5 min read</p></div></li>
</ul>

18Responsive ratio

A small custom class changes --ui-aspect-ratio per breakpoint: square on phones, 21:9 on tablets and up.

<div class="ratio hp-ratio-resp rounded-lg overflow-hidden">
  <img src="https://images.unsplash.com/photo-1753162657329-beced5a7f63f?auto=format&fit=crop&w=1600&h=700&q=70" alt="Ideas worth talking about" class="object-cover">
</div>

19Round avatars

ratio-1x1 with rounded-circle keeps profile pictures perfectly round even when the source is not square.

Samir

Liam

Tariq

Leo

<div class="flex flex-wrap gap-4">
  <div class="text-center" style="width:5rem">
    <div class="ratio ratio-1x1 rounded-full overflow-hidden border border-2 border-primary">
      <img src="../assets/img/avatar-6.svg" alt="Samir Tanaka" class="object-cover">
    </div>
    <span class="small block truncate mt-1">Samir</span>
  </div>
  <div class="text-center" style="width:5rem">
    <div class="ratio ratio-1x1 rounded-full overflow-hidden border border-2 border-primary">
      <img src="../assets/img/avatar-12.svg" alt="Liam Duarte" class="object-cover">
    </div>
    <span class="small block truncate mt-1">Liam</span>
  </div>
  <div class="text-center" style="width:5rem">
    <div class="ratio ratio-1x1 rounded-full overflow-hidden border border-2 border-primary">
      <img src="../assets/img/avatar-10.svg" alt="Tariq Novak" class="object-cover">
    </div>
    <span class="small block truncate mt-1">Tariq</span>
  </div>
  <div class="text-center" style="width:5rem">
    <div class="ratio ratio-1x1 rounded-full overflow-hidden border border-2 border-primary">
      <img src="../assets/img/avatar-3.svg" alt="Leo Tanaka" class="object-cover">
    </div>
    <span class="small block truncate mt-1">Leo</span>
  </div>
</div>

20Loading skeleton

A 16:9 placeholder block with placeholder-glow while the real image and text load.

The skeleton reserves the exact space, so the page does not jump when content arrives.

<div class="card" style="max-width:22rem" aria-hidden="true">
  <div class="ratio ratio-16x9 placeholder-glow">
    <span class="placeholder"></span>
  </div>
  <div class="card-body placeholder-glow">
    <span class="placeholder col-7 mb-2"></span><span class="placeholder col-4"></span>
  </div>
</div>
<p class="small text-muted mt-2 mb-0">The skeleton reserves the exact space, so the page does not jump when content arrives.</p>