Aspect Ratio Calculator
Simplify a width and height to a ratio, and resize without distortion.
Enter values
px
px
px
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Step by step
The formula
ratio = w : h (reduced); new height = new width × h / w
An aspect ratio is width to height reduced to its simplest form. Keeping it fixed while resizing is what prevents images and video from stretching — change one dimension and the other must move by the same proportion.
All calculations run locally in your browser and update instantly as you type.
Example calculations
Common questions this calculator answers — select one to load its values.
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Frequently asked questions
How do I resize without stretching?+
Keep the ratio: new height = new width × (original height ÷ original width). Enter your target width and the tool fills in the matching height.
All calculations run locally in your browser. Nothing you type is sent to a server.