Aspect Ratio Resize Calculator
Keeps an image or video in proportion when you change its size.
New size
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Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
Scale — %
Cropped off the width — px
Cropped off the height — px
The formula
new height = new width × height ÷ width
To fit a box, scale by the smaller of the two box-to-image ratios. To fill it, scale by the larger and crop the overflow.
What to watch out for
Results round to whole pixels, so very small sizes can drift slightly from the exact ratio.
Frequently Asked Questions
What height keeps 1920 × 1080 in shape at 1280 wide?
720 pixels.
What is the difference between fit and fill?
Fit shows the whole image and may leave bars. Fill covers the box and crops whatever sticks out.