Aspect Ratio Calculator
Last updated: June 8, 2026Resize keeping the same ratio.
Aspect Ratio Calculator is a free online calculator to resize keeping the same ratio. It runs entirely in your browser, so your files never leave your device — nothing is uploaded. There's no sign-up, no watermark, and it works on any modern browser on desktop or mobile.
How to use Aspect Ratio Calculator
The Aspect Ratio Calculator finds the simplified ratio of any dimensions and calculates a new width or height that keeps the same ratio, with no distortion. Ideal for resizing images, video and screens. Free and runs in your browser.
Read the full guide: Aspect Ratio Calculator: Resize Without Distortion
- 1Enter your original width and height.
- 2See the simplified aspect ratio.
- 3Enter a new width to get the matching height.
No distortion
Find the exact height (or width) that preserves the ratio.
Simplified ratio
See ratios like 16:9 from any dimensions.
Free & private
Runs on your device with no sign-up.
Scale a thumbnail without stretching
You shot a 1920x1080 frame but your upload slot needs it 1280 wide. Enter the original dimensions to confirm the 16:9 ratio, then type 1280 as the new width and the calculator returns 720 as the exact matching height. Resize your image or video to those numbers and it stays perfectly sharp, with no squashing, black bars, or awkward platform cropping.
Identify an unknown screen ratio
Not sure if a monitor is 16:9, 16:10, or ultrawide? Type the native resolution into the original size fields and the tool simplifies it instantly using the greatest common divisor. A 2560x1600 panel resolves to 16:10, while 3440x1440 reveals 21:9. Handy when buying a display, picking wallpaper dimensions, or checking that game and video settings actually match the hardware.
Fit artwork into a fixed frame
Designing a banner, print, or web container with a set width but an unknown height? Plug your source artwork's dimensions in as the original size to lock its ratio, then enter the exact target width your layout demands. The matching height appears immediately, so you can size a canvas or placeholder that holds the image proportionally rather than cropping or distorting it to force a fit.
Aspect Ratio Calculator — frequently asked questions
How do I keep the aspect ratio when resizing?
Enter the original size, then a new width — the tool calculates the height that keeps the same ratio so the image isn't stretched.
What aspect ratio is 1920x1080?
16:9 — the standard widescreen ratio. The tool simplifies any dimensions for you.
Is it free?
Yes, completely free.
Share this tool
Send it to someone who needs it or save the link for later.
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