How to resize a photo to exact pixels (600×600, 413×531 and more)
Updated 2026-09-30
Resizing to exact pixels fails when the photo has a different shape from the target. Force it and the picture stretches. Crop to the target shape first, then resize.
- Work out the shape of the target. 600 × 600 is a square. 413 × 531 is about 7 wide to 9 high.
- Crop your photo to that shape with Prepare a photo, which has a crop box locked to the shape you choose.
- Set the exact size. Prepare a photo does the crop and the resize together. For a plain resize use Resize image.
- If the form also has a file-size limit, finish with Compress image to target size.
From millimetres to pixels
Pixels = millimetres ÷ 25.4 × DPI. At 300 DPI, 35 × 45 mm is 413 × 531 pixels and 50 × 70 mm is 591 × 827 pixels. The size guide has a full table.
Pixel sizes on a form are the only thing you have to match on screen. Millimetres only matter for prints, where the DPI decides how many pixels you need.
Frequently asked questions
- How do I resize a photo to 600×600 pixels?
- Crop it to a square, then set the size to 600 × 600. Prepare a photo does both with a custom size.
- Why does my photo look stretched after resizing?
- The width and height were changed by different amounts. Crop to the target shape first.