Aspect Ratio Calculator
Resize dimensions without distorting the ratio.
Free · No sign-up · Works in your browser
About the Aspect Ratio Calculator
Calculate aspect ratios free — enter your original width and height (or tap a preset like 16:9, 9:16, or 1:1) and type the new width or height you need; the other dimension fills in automatically so nothing gets stretched or squashed. You also get the simplified ratio (1920×1080 → 16:9). Essential for resizing video, scaling images for social formats, and setting responsive embed dimensions.
How to use the Aspect Ratio Calculator
- 1Enter the original width and height (or pick a preset like 16:9).
- 2Type the new width or height you want.
- 3The other dimension fills in automatically, keeping the ratio locked.
Frequently asked questions
What is an aspect ratio?
It's the proportional relationship between width and height, written like 16:9. Keeping it constant prevents stretching or squashing when you resize images and video.
Which ratios are most common?
16:9 for YouTube and monitors, 9:16 for Stories/Shorts/Reels, 1:1 for Instagram feed, 4:3 for classic displays, and 21:9 for ultrawide.