Aspect Ratio Calculator
Type one dimension and get the other, locked to 16:9, 4:3, 1:1, 21:9 or a ratio you define — so images and videos scale without stretching.
How to use the Aspect Ratio Calculator
- Enter the original width and height, or pick a standard ratio.
- Type the new width (or the new height) you need.
- The matching dimension appears instantly, rounded to whole pixels.
About the Aspect Ratio Calculator
Whenever you resize a thumbnail, export a video or crop a banner, keeping the original proportion is what stops faces looking squashed. This calculator solves for the missing side and also reduces any pair of pixel dimensions to its simplest ratio, which is handy when you inherit a file and need to know what ratio it actually is before choosing an export preset.
Frequently asked questions
What size is 16:9 at 1080 pixels tall?
1920 × 1080. Enter 1080 as the height with the 16:9 ratio selected and the width is calculated for you.
How do I find the aspect ratio of an image?
Enter its pixel width and height — the tool reduces them to the simplest ratio, such as 3000×2000 becoming 3:2.
Why do my images look stretched after resizing?
Because the width and height were changed by different amounts. Use one dimension as the input here and take the other from the result.
Can I work out a new resolution from an existing one?
Yes. Enter the original width and height, then type either the new width or the new height and the missing value is calculated for you. Used as a resolution scaler this is how you resize to 1920x1080 or 1080x1350 without distorting the image.
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