Find the frame.
Keep the ratio.
Calculate a simplified aspect ratio, read an image's real dimensions, and work out the missing side for a new canvas. Everything runs locally.
Aspect ratio calculator
Find the missing dimension
Choose a target ratio and enter one side. The other side is calculated without distortion.
A 16:9 canvas is 1.78 times as wide as it is tall.
Aspect ratio is width ÷ height. The calculator rounds a missing pixel dimension to the nearest whole pixel; it does not crop or resize the source image.
What does 16:9 mean?
For every 16 units of width, the frame has 9 units of height. A 1,920 × 1,080 image and a 1,280 × 720 image both use 16:9.
Can this crop my image?
No. This page calculates dimensions only. Use the main image tool's crop mode when you need to fill a fixed frame and remove the excess edges.
Is my image uploaded?
No. The optional image picker uses the browser's local image decoder to read natural width and height. The file is not sent to a server.