Image Resize Calculator

The image resize calculator works out new pixel dimensions that keep an image in proportion, so it never looks stretched or squashed when you scale it. Every image has an aspect ratio, the relationship between its width and its height, and the trick to resizing cleanly is to change both dimensions by the same factor. This tool does that for you. Enter the original width and height, then give the new size you want for just one side, either a target width or a target height, and the calculator finds the matching value for the other side along with the scale percentage that links the old size to the new one. That percentage tells you at a glance whether you are shrinking the image, where a value under 100 means smaller, or enlarging it, where a value over 100 means bigger and a likely loss of sharpness. Web developers sizing images for a layout, photographers preparing exports, and anyone fitting a picture into a fixed space use it to plan dimensions before they touch an editor. A few tips keep results crisp. Prefer scaling down rather than up, because enlarging cannot add detail that was not captured and tends to look soft. Round the result to whole pixels, since you cannot have a fraction of a pixel on screen. When you need an exact box that does not match the original ratio, decide whether to crop or to pad rather than forcing a stretch, which distorts faces and text. This tool runs entirely in your browser, so no image or measurement is uploaded, and it works purely on the numbers you enter.

New dimensions keep the original aspect ratio. Scale = new width / original width.