16:9 Aspect Ratio Calculator

A 16:9 frame is sixteen units wide for every nine units tall. Divide 16 by 9 and you get a value of roughly 1.778, so any image whose width is about 1.78 times its height is a 16:9 image. Turned on its side the same rectangle becomes 9:16, which is the portrait shape used by phone video.

The ratio describes shape, not size. A 640 × 360 clip and a 3840 × 2160 clip are both 16:9 even though one has 36 times the pixels of the other. That is why 16:9 carries across resolution changes: 720p, 1080p, 1440p, 4K and 8K all share the same shape, so existing footage does not have to be re-cropped when a new display generation arrives.

1. You know the size and want it checked. Open the Dimensions → Ratio tab and type your width and height. The tool divides out the greatest common divisor and tells you whether you are truly on 16:9 or merely close to it — a 1366 × 768 laptop panel, for instance, reports 683:384 rather than a clean 16:9.
2. You know one side and want the other. Switch to Resize by Ratio, leave the ratio at 16:9 and type the width or height you already have. The missing dimension is filled in and rounded to a whole pixel, because a screen cannot draw half of one.
3. You want the code or the numbers. Copy Ratio gives you the simplified fraction, Copy Dimensions gives you the exact pixel pair, and Copy CSS hands you a ready-made aspect-ratio declaration to paste into a stylesheet.

Every calculation runs in your browser. Nothing is uploaded, so you can check a client's file or an unreleased export without sending it anywhere.

You do not need a calculator app to work out a 16:9 size, but the arithmetic is easy to get wrong when you start from an odd number.

1. Take the width you want to keep and divide it by 16.
2. Multiply that result by 9 to get the matching height.
3. Round the height to the nearest whole pixel — half pixels do not exist on a screen.

Worked example

Starting from 1920 pixels wide: 1920 ÷ 16 = 120, then 120 × 9 = 1080. The matching height is 1920 × 1080. Working from 2560: 2560 ÷ 16 = 160, and 160 × 9 = 1440, giving the 2560 × 1440 monitor size. If you already know the height instead, divide by 9 and multiply by 16 — 720 ÷ 9 = 80, and 80 × 16 = 1280.

The biggest mix-up is assuming any "widescreen" video or display is 16:9. Most theatrical film is actually shot at 1.85:1 (flat widescreen) or 2.39:1 (anamorphic scope), both noticeably wider than 16:9 — that's why movies still show letterbox bars on a 16:9 TV. On the display side, a 1366 × 768 laptop panel is marketed as 16:9 but reduces to 683:384, about 0.05% wider than true 16:9 — invisible to the eye but enough to throw off pixel-exact layouts. The other common error is confusing 16:9 (1.778) with 16:10 (1.6); the numbers look similar but 16:10 is a visibly taller frame, common on MacBooks and business laptops rather than TVs or streaming video.

To fit 16:9 to a 4K master: 3840 ÷ 16 = 240, then 240 × 9 = 2160. That gives 3840 × 2160 — 4K UHD, the resolution most cinema cameras and streaming platforms deliver, and an exact 16:9 frame.

Type your own numbers into the 16:9 calculator above and it will show the same division, plus the reduced ratio and the CSS to copy.

• YouTube and Vimeo uploads, where 1920 × 1080 is a common master size.
• Television broadcasts and streaming platforms, which commonly deliver 16:9.
• Laptop and desktop monitors, from 1366 × 768 budget panels up to 3840 × 2160.
• Video thumbnails and social share cards, which are cropped to 16:9 by most platforms.
• PowerPoint and Keynote widescreen decks, which use a 16:9 widescreen slide size.
• Web hero banners and video embeds that need to fill a 16:9 container without letterboxing.

Need a wider frame? See 21:9 and 2.39:1, or a taller one with 16:10.

Landscape ratios are closely related. If you need the vertical version of this shape, the 9:16 calculator handles portrait video; 21:9 and 16:10 are the widescreen variants used by ultrawide monitors and modern laptops.

• 9:16
• 4:3
• 1:1
• 16:10
• 21:9
• 3:2
• 4:5
• 2:3
• 2.39:1

This 16:9 guide is one of ten ratio calculators on the site — the common aspect ratios table lists the decimal value and the typical uses for every one of them.

Every row keeps the full width and trims the height, which is the least destructive way to reach a wider shape — you keep every horizontal pixel you already have. If you need to keep the height instead, perhaps because a video timeline is locked, switch to Resize by Ratio and let the calculator work out the new width.

Add a free, live aspect ratio calculator to any page in one line of code - no account, no API key, no ads. Every embed credits the tool with a Powered by AspectCalc link, so your readers always know where it came from. See the full embedding guide for height and styling options.

<div class="aspectcalc-embed" style="max-width:100%">
  <iframe id="aspectcalc-frame" src="https://aspectcalc.com/embed?h=640"
          width="100%" height="700" style="border:0;border-radius:12px"
          loading="lazy" title="AspectCalc aspect ratio calculator"></iframe>
  <p style="margin:8px 0 0;font:13px/1.4 system-ui,sans-serif;color:#64748b;text-align:center">Powered by <a href="https://aspectcalc.com/" style="color:#2563eb;text-decoration:none">AspectCalc</a> - free aspect ratio calculator</p>
</div>
<script>
  // Optional: grow the frame to the widget's real height.
  // Delete this whole block to keep a fixed-height frame instead.
  addEventListener('message', function (e) {
    if (e.origin !== 'https://aspectcalc.com') return;
    if (!e.data || e.data.type !== 'aspectcalc-height') return;
    var f = document.getElementById('aspectcalc-frame');
    if (f) f.style.height = e.data.height + 'px';
  });
</script>

The frame starts at a fixed height, so your layout never jumps. Resize it with ?h= - for example https://aspectcalc.com/embed?h=520 - or keep the small script in the snippet and the frame will follow the widget's real height instead.