Aspect Ratio Calculator

About Aspect Ratio Calculator

An aspect ratio calculator works out the proportion between width and height and helps you resize an image or video without distortion. Enter an original width and height to see the simplified ratio like 16:9 or 4:3, then type a new width or height and the other dimension is solved to match — so nothing stretches. It's handy for images, video, screens, and print, and runs entirely in your browser.

Frequently asked questions

How do I resize an image without stretching it?

Keep the same aspect ratio. Enter the original width and height, then type your target width — the calculator gives the matching height (or vice versa) so the image stays in proportion.

How do I calculate height from width for 16:9?

Multiply the width by 9 and divide by 16 (height = width × 9 ÷ 16). A 1920px-wide 16:9 frame is 1080px tall. Enter the width here and the height is filled in automatically.

What is an aspect ratio?

It's the proportional relationship between width and height, written as two numbers like 16:9. A 1920×1080 image and a 1280×720 image share the same 16:9 ratio even though the pixel sizes differ.

What are common aspect ratios?

16:9 for most video and screens, 4:3 for older displays and photos, 1:1 for square social posts, and 21:9 for ultrawide. The calculator simplifies whatever width and height you enter.

Is anything uploaded?

No. The math runs entirely in your browser — no images or numbers are sent anywhere.