Aspect Ratio Calculator
Work out the matching width or height for a given aspect ratio, and read the ratio back out of a resolution you already have.
Common ratios
Edit either side and the other follows.
- Ratio
- 16:9
- As a decimal
- 1.778
Close to Widescreen 16:9
Common resolutions
Files are processed in your browser and are never uploaded to a server.
How to use
Free to use with no sign-up, no install and no usage limit.
Choose a ratio and fill in one side. The other appears immediately, rounded to a whole pixel, since no image is ever 56.25 pixels tall.
Getting this wrong is visible straight away. A video that does not match its frame either gets black bars down the sides or has the picture stretched to fit, and both are obvious to anyone watching.
The tool also runs the other way: type a resolution you already have and the ratio comes back reduced. 1920 × 1080 reads as 16:9 rather than 1920:1080, which is what makes it useful.
Some resolutions do not reduce neatly. 1366 × 768 comes out as 683:384, so the nearest familiar ratio is named alongside it — nobody recognises 683:384 as roughly widescreen.
Ratios can be written with a colon, a slash or an x, because all three turn up in specs and none of them is more correct than the others.
Nothing you type is sent to a server. Everything is calculated inside your browser.