How to find an aspect ratio
- Enter the Width and Height in pixels, or in any unit as long as both use the same one.
- To resize, type the width you want in New width, or the height you want in New height. Leave both empty if you only need the ratio.
- Read the simplified ratio, the ratio as a decimal, the closest common ratio if yours is near one, and the other side that keeps the shape at your new size.
Common aspect ratios and sizes
| Ratio | Common sizes | Where you see it |
|---|---|---|
| 16:9 | 1280 × 720, 1920 × 1080, 3840 × 2160 | TVs, monitors, YouTube, presentations |
| 16:10 | 1440 × 900, 1920 × 1200 | Many laptop screens |
| 4:3 | 1024 × 768, 1600 × 1200 | Older monitors, many phone camera photos, tablets |
| 3:2 | 3000 × 2000, 6000 × 4000 | Many camera sensors, 6 × 4 inch prints |
| 1:1 | 1080 × 1080 | Square social media posts |
| 4:5 | 1080 × 1350 | Portrait social media posts |
| 9:16 | 1080 × 1920 | Stories, Reels, TikTok, Shorts |
“21:9” ultrawide monitors aren’t exactly 21:9. 2560 × 1080 is really 64:27 and 3440 × 1440 is 43:18. Both are sold as 21:9 because it’s the nearest round name. For both, the calculator shows the exact ratio with 21:9 as the closest common ratio.
Rounding the new size
The new height is shown to two decimal places, because it often doesn’t come out whole. 1000 pixels wide at 16:9 gives 562.5. Pixels have to be whole, so round to the nearest number. For video, round to an even number, since many video encoders reject odd widths or heights.
If the shape you need is different from the shape you have, resizing alone will stretch the picture. Crop first to the target ratio, then resize. A 4:3 photo going into a 16:9 slide either needs cropping top and bottom or bars down the sides.