Aspect Ratio Calculator
Resize width or height while keeping aspect ratio.
How to use the Aspect Ratio tool
- Enter your aspect ratio in the fields above.
- Adjust any slider or type an exact number — the answer updates as you go.
- Copy the result and close the tab. Nothing you entered was sent anywhere.
About the Aspect Ratio tool
Enter the original dimensions and a new width or height; the matching dimension is computed with rounding, and the closest simple ratio (like 16:9) is shown.
Simplification uses the greatest common divisor, so 1920 × 1080 correctly reduces to 16:9 rather than an unwieldy fraction.
Everything runs locally in your browser: no data is uploaded, no account is needed, and it works offline once the page has loaded.
Embed this tool
Customize and copy an iframe. Linking back helps both sites.