Image resize calculator
Enter the original size and a new width or height; it keeps the ratio.
Resize an image keeping the aspect ratio
This calculator works out the new width or height while keeping the original image’s aspect ratio, so it won’t distort, and gives the scale in %. Change one side and the other adjusts automatically.
How it’s calculated
new height = new width × (original height / original width)
For example, from 1920×1080 to a width of 1280 → height 720 (still 16:9, 67% scale).
What it’s for
- Fit images to a max width without distortion.
- Work out dimensions for web, social or print.
- Know the scale percentage versus the original.
Frequently asked questions
Does it keep the ratio? Yes: changing one side recomputes the other from the original ratio.
Does it resize the file? No: it computes the dimensions; do the actual resize in your editor.