Open Kuro

Aspect ratio calculator

Pick a ratio and type a width or a height to get the other side. Or type any size into the ratio boxes to see its shape.

1920 × 1080

Common aspect ratios

RatioAt 1080 pixelsWidth ÷ heightUsed for
16:91920 × 10801.778YouTube, TV and most laptop screens
9:161080 × 19200.563TikTok, Reels, Shorts and Stories
1:11080 × 10801.000Square posts
4:51080 × 13500.800Instagram feed posts
4:31440 × 10801.333Standard-definition TV and most phone photos
3:41080 × 14400.750Phone photos held upright
3:21620 × 10801.50035 mm film and most camera photos
2:31080 × 16200.667Upright camera photos and Pinterest pins
21:92520 × 10802.333Ultrawide monitors and cinema-style video

How it works

  1. Pick a ratio, or type your own into the two ratio boxes, such as 1920 and 1080.
  2. Type a width or a height. The other side is worked out as you type.
  3. Read the size, its simplest ratio and the common shape it's near, then make a clip or an image at that shape in Kuro.

Questions

How do I work out an aspect ratio?

Divide the width and the height by the largest number that goes into both. 1920 and 1080 both divide by 120, into 16 and 9, so 1920 × 1080 is 16:9. Type any size into the ratio boxes and the calculator does it.

How do I find the height for a width?

Multiply the width by the ratio's second number and divide by its first. At 16:9, a width of 1280 gives 1280 × 9 ÷ 16 = 720.

Why are some sizes rounded to an even number?

When the arithmetic doesn't land on a whole pixel, the calculator rounds to the nearest even number, because H.264 video, as phones and platforms make it, needs even widths and heights. 16:9 at 480 pixels tall is 853.3 wide, so it shows 854.

Is a 21:9 monitor really 21:9?

Not quite. Ultrawide screens sold as 21:9 are 2560 × 1080 (64:27, 2.37 to 1) or 3440 × 1440 (43:18, 2.39 to 1), while 21:9 itself is 2.33 to 1. Type either size into the ratio boxes: the calculator shows its exact ratio and that it's near 21:9.

Does anything get uploaded?

There's nothing to upload. It's arithmetic, done by this page in your browser.

Resize a video

Turn a video into 9:16 for TikTok, Reels and Shorts, or 4:5, 1:1 or 16:9.

Crop a video

Cut a video down to the part you want to keep, at its own size.

Safe-zone checker

See where TikTok, Reels and Shorts will cover your video before you post.

Trim a video

Cut a video down to the part you want, in seconds.