How to use the aspect ratio calculator
- To find a ratio, type a width and a height. The simplified ratio, such as 16:9, appears at once.
- To resize, pick a preset like 16:9, 4:3, or 9:16, or type your own ratio.
- Type the new width or the new height. The other side is calculated so the picture is not stretched.
The preview box shows the shape of the ratio. Results with decimals are rounded to two places, and the nearest whole-pixel size is shown underneath for images and video.
Questions
Is anything I type sent anywhere?
No. The sums are done in your browser. Nothing is uploaded or tracked.
How do I find the aspect ratio of an image or screen?
Divide the width and the height by their greatest common divisor. For 1920 × 1080 that divisor is 120, which gives 16:9. Type the width and height into the first box and the simplified ratio appears.
How do I resize a picture without stretching it?
Pick the ratio (or use the one you just found), then type the new width. The height is filled in so the shape stays the same: 1280 wide at 16:9 is 720 high. Type a height instead and the width is worked out.
Why does my size give an odd ratio like 683:384?
Some sizes, such as 1366 × 768, are only close to a standard shape, so the exact ratio does not reduce to small numbers. The tool shows the nearest common ratio (here 16:9) next to the exact one.
Which aspect ratios are most common?
16:9 is used for most video, monitors, and YouTube. 4:3 is the older TV and tablet shape, 1:1 is square for profile pictures, 9:16 is vertical video for phones, 21:9 is ultrawide, and 3:2 is typical for photos from cameras.
Credits
Built by OneTooling using standard browser features. No third-party code runs on your data.