Aspect Ratio Calculator
Enter a width and height to get the simplified aspect ratio and the decimal ratio, and work out the matching dimension when you scale to a new width or height.
- Runs entirely in your browser
- No sign-up, no watermark
- Free and unlimited
🔒 Your file stays on your device
How to use Aspect Ratio Calculator
- 1
Open Aspect Ratio Calculator and fill in the fields.
- 2
Pick any options that apply.
- 3
Read the result straight away — it recalculates as you type.
What you get
- Simplified ratio (e.g. 16 : 9)
- Decimal ratio
- Scaled width or height for a resize
What happens to your files
This tool runs entirely in your browser. The file you choose is read into memory, processed on your device, and offered back as a download. Nothing is uploaded and nothing is kept once you leave the page.
There is no account, no email, no watermark and no daily limit. Come back whenever you need it.
Frequently asked questions
- How is the ratio simplified?
- The width and height are rounded to whole pixels and divided by their greatest common divisor, so 1920×1080 becomes 16 : 9.