Image Aspect Ratio Calculator
Type a width and height to get the ratio, or resize while keeping it. You can also drop an image to read its size.
Ratio of a size
—Aspect ratio
—Decimal
—Closest standard
Resize keeping the ratio
Change either value — the other one follows the ratio above.
Common ratios
Or drop an image to read its dimensions
● This calculator runs entirely in your browser. Dropped images are read locally and never uploaded.
How it works
The aspect ratio is the width divided by the height, reduced to the smallest whole numbers with the greatest common divisor — 1920×1080 becomes 16:9. When the exact fraction is awkward (like 1366×768), the closest standard ratio is shown too.
FAQ
What's the ratio of 1080×1350?
4:5, the Instagram portrait format.
Is 1366×768 really 16:9?
Almost — it's 683:384, about 1.779, which is within 0.1% of 16:9 (1.778).