How to Resize an Image Without Stretching It

The aspect-ratio rule

A picture’s aspect ratio is width divided by height. If you change width and height by the same factor, the ratio stays the same and nothing looks stretched. In practice: pick a new width, then the new height is

new height = new width × original height ÷ original width

For a 4032 × 3024 photo resized to 800 wide: 800 × 3024 ÷ 4032 = 600. So 800 × 600, and the shape is unchanged. In Resize Image, typing just a width does this for you.

When the target has a different shape

Often you’re asked for a shape the photo doesn’t have, such as a square (1:1) from a 4:3 photo. You can’t keep every pixel and the ratio and the target. You choose which to give up:

• Crop to fit gives up the edges. The picture is scaled until it covers the target, and the overflow is cut. Best for photos; you pick which part stays.
• Fit inside gives up the exact fill. The whole picture is scaled to fit, with bands of a background colour you choose. Best when no edge can be lost, like a document or signature.
• Stretch gives up the shape, and it shows. Use it only when distortion doesn’t matter.

Example: 4032 × 3024 to 500 × 500.

• Crop to fit: scale to 500 tall (so 667 wide), then cut the width down to 500, a quarter of it removed.
• Fit inside: scale to 500 wide (so 375 tall), centred, with a band of about 62 pixels above and below.

Steps

1. Add the picture in Resize Image.
2. For a free shape, type only one side.
3. For a fixed shape, type both and choose Crop to fit or Fit inside. With Crop, drag the box.
4. Check the preview before you download.

If you only need to cut part of the picture out, Crop Image lets you drag the box freely, use a ratio like 4:5, or lock an exact size.

Don’t confuse it with file size

Changing the shape or size changes the pixels, which changes the file size. But an exact size doesn’t mean an exact KB. If the form fixes both, see image dimensions vs file size.