Aspect Ratio Calculator
Enter the original width and height, then the new width you want. The calculator finds the height that keeps the same proportions, and shows the aspect ratio in its simplest form.
Type a number and the answer appears straight away.
New size1,280 x 720
- Aspect ratio
- 16:9
- As a decimal
- 1.778:1
- Scale
- 66.7% of the original
- Pixels (if these are pixel sizes)
- 921,600
The math behind it: Aspect Ratio
new height = new width x original height / original width
An image 1920 by 1080 has an aspect ratio of 16:9. Resized to a width of 1280, its height becomes 720. Keeping the ratio the same is what stops pictures and videos from looking squashed or stretched.
Common questions
How do I calculate aspect ratio?
Divide the width and the height by their greatest common factor. For 1920 by 1080 that factor is 120, giving 16:9.
How do I resize an image without stretching it?
Change the width and height by the same proportion. Multiply the new width by the original height and divide by the original width to get the new height.
What is the difference between 16:9 and 4:3?
16:9 is the widescreen shape used by modern TVs, monitors and most video. 4:3 is the squarer shape of older TVs and many tablets.
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