Crop a photo to a print size
For that print shape the photo is cropped to 5,000 px by 4,000 px, which loses 16.7 % of the picture and leaves 20.0 MP.
Result
Width after the crop
px
Height after the crop
px
Picture lost
%
| 3:2 (4 × 6 in) | 0.0 % |
|---|---|
| 4:3 (6 × 8 in) | 11.1 % |
| 5:4 (8 × 10 in) | 16.7 % |
| 7:5 (5 × 7 in) | 6.7 % |
| 14:11 (11 × 14 in) | 15.2 % |
| ISO A series paper | 5.7 % |
| Square | 33.3 % |
| Wide screen | 15.6 % |
How it works
Print sizes have fixed shapes and photos rarely match them. A camera photo is three to two, a phone photo four to three, while an eight by ten print is five to four. To fill the sheet the tool keeps the whole of the short side and cuts the long side, or the other way round, to reach the print shape, always from the center of the photo. It reports the pixels left, how many are trimmed from each direction and the share of the picture lost. The list below shows the same photo for every common print shape, so you can pick the shape that loses least. To crop a 3:2 photo to 8x10, or to see how much is cropped for 4x6 (8 × 10 and 4 × 6 inches), pick the shape: the photo aspect ratio for an 8x10 print is five to four.
Formula
Let a = max(px_w, px_h) and s = min(px_w, px_h) (the photo's long and short side) and r = the target's long side over short side (r >= 1; for custom the larger custom side over the smaller). If a / s > r the photo is too long: the long side becomes s x r and the short side stays s. Otherwise it is too short: the short side becomes a / r and the long side stays a. The result is turned back to the photo's own orientation (crop_w along px_w). loss = 1 - crop_w x crop_h / (px_w x px_h). trim_w = px_w - crop_w, trim_h = px_h - crop_h, megapixels_after = crop_w x crop_h, returned in px (the MP display unit divides by 1,000,000). The table lists loss for every listed ratio. The warning w_no_crop appears when loss < 0.001.
Worked example
The tool opens with this example; the result above is computed from it.
| Input | Value |
|---|---|
| Photo width in pixels | 6,000 px |
| Photo height in pixels | 4,000 px |
| Print shape | 5:4 (8 × 10, 16 × 20 in) |
| Width after the crop | 5,000 px |
| Height after the crop | 4,000 px |
| Picture lost | 16.7 % |
Common cases
| Case | Starting values | Width after the crop | Height after the crop | Picture lost |
|---|---|---|---|---|
| Camera photo for an eight by ten | Photo width in pixels 6,000 px; Photo height in pixels 4,000 px | 5,000 px | 4,000 px | 16.7 % |
| Phone photo for a four by six | Photo width in pixels 4,032 px; Photo height in pixels 3,024 px | 4,032 px | 2,688 px | 11.1 % |
| Camera photo for an A-size sheet | Photo width in pixels 6,000 px; Photo height in pixels 4,000 px | 5,657 px | 4,000 px | 5.7 % |
| Portrait photo for an eight by ten | Photo width in pixels 3,000 px; Photo height in pixels 4,500 px | 3,000 px | 3,750 px | 16.7 % |
Questions and answers
How do I crop a photo for an 8 × 10 print?
A camera photo of 6,000 px by 4,000 px is wider than an eight by ten sheet, so the long side is trimmed to 5,000 px by 4,000 px: 1,000 px comes off the width and 16.7 % of the picture is lost.
How much of a phone photo is cropped for a 4 × 6 print?
A phone photo of 4,032 px by 3,024 px is four to three and a four by six print is three to two, so it is cropped to 4,032 px by 2,688 px and 11.1 % of the picture is lost.
Assumptions and limits
- The crop is taken from the center. Moving it along the long side changes which part is lost, not how much.
- Portrait and landscape are treated alike: the print shape is turned to match the photo.
- Sizes in inches are grouped by the shape of their sides, for example eight by ten and sixteen by twenty are both five to four.
The result is an estimate for planning, not professional advice.
Sources
- Aspect ratio (image) (Wikipedia): definition as width to height; 3:2 and 4 x 6 prints, 4:3, 5:4 and 8 x 10 prints, 1:1, 16:9retrieved 2026-10-13
- ISO 216 (Wikipedia): the A series has aspect ratio square root of tworetrieved 2026-10-13
Last updated:
Method in depth: Print shapes and cropping
Cite this page: Frame Kit, “Crop a photo to a print size”, https://frame-kit.pages.dev/photo-print/crop-a-photo-to-a-print-size/ (updated 13 October 2026).
Found a mistake? Email handycalc.sites+framekit@gmail.com.