20 · Calculators

Aspect Ratio Calculator

Enter a width and height to get the simplified aspect ratio, then type a new width or height to resize it without distortion.

Resize to keep the same shape

Aspect ratio

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How to use the aspect ratio calculator

  1. Enter the original width and height, or tap a common ratio.
  2. Type a new width to get the matching height, or a new height to get the width.
  3. Use the resized size in your image editor, video export or CSS.

Common aspect ratios

  • 16:9 — HD and 4K video, most monitors and TVs.
  • 9:16 — vertical video for Reels, TikTok and Shorts.
  • 4:5 — portrait posts on Instagram.
  • 1:1 — square images and profile pictures.
  • 4:3 — older screens, many tablets and photos.
  • 21:9 — ultrawide monitors and cinema.

Examples

1920 × 1080 resized to 1280 wide

16:9 → 1280 × 720

1080 × 1350

4:5

Questions

Why do I get decimals when resizing?

Not every width divides evenly. Round to the nearest whole pixel; the difference won’t be visible.

Can I use other units?

Yes. Ratios work the same for inches, centimetres or any unit, even though the fields say px.

What about 1366 × 768?

Its exact ratio is 683:384, which is very close to 16:9. Many “16:9” screens are approximate like this.