Aspect Ratio Calculator
Enter a ratio like 3:2 or 16:9 and one known dimension to solve the other while keeping proportions, and see the simplified ratio.
Type a ratio such as 3:2, 16:9, or 4:5, pick which dimension you know, and get the matching size that keeps the frame proportions intact — handy for crops, prints, and video exports.
How it works
An aspect ratio is just the relationship between width and height — 3:2 for most cameras, 16:9 for video, 4:5 for a tall social post. Keep that relationship fixed and an image looks right at any size.
Type your ratio and the one dimension you already know, then pick whether you're solving for width or height. The tool scales the known side by the ratio to give you the matching value with no distortion.
It also reduces whatever ratio you enter to its simplest whole-number form, so 1920:1080 comes back as 16:9. That's a quick sanity check that two sizes really share the same shape.
Frequently asked questions
How do I type the ratio?
Use a colon like 3:2, but a slash or an x works too. The calculator strips out the separator and just reads the two numbers on either side.
Can it handle non-standard ratios?
Yes. Any positive pair works, so you can enter something odd like 7:3 for a panorama and it scales your dimension to match exactly.
Why does resizing without a fixed ratio look wrong?
Changing width and height independently stretches or squashes the image. Locking the ratio keeps circles round and faces natural, which is why matching proportions matters.