Aspect Ratio Calculator
Enter the original width and height of an image, video, or design frame, then type either a new width or a new height — the other dimension is calculated instantly so the proportions stay exact. It also shows the simplified aspect ratio (like 16:9) for reference.
How it works
Type the original width and height, then switch to whichever dimension you want to change and enter the new value. The calculator keeps the width-to-height ratio identical and rounds the other dimension to the nearest whole pixel.
Tip
The simplified ratio (e.g. 1920×1080 → 16:9) is handy for picking a matching frame size or checking whether two images share the same proportions at a glance.
Why is the result rounded?
Pixel dimensions have to be whole numbers, so the calculated side is rounded to the nearest pixel — for very small sizes this can shift the exact ratio by a fraction of a percent.
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