Sizes
| Size (in) | Size (cm) | Ratio | Mpix | Shutterfly | Walgreens |
|---|---|---|---|---|---|
| 4 x 6 | 10.2 x 15.2 | 2:3 | Print. 400 x 600 minimum, 1000 x 1500 optimal. | Print. 640 x 480 minimum, 1024 x 768 listed for 4x6. | Print. 540 x 360 minimum. |
| 4 x 5.3 | 10.2 x 13.5 | 40:53 | Print. No pixel size published. | Not listed. | True Digital print. No pixel size published. |
Centimetres use 1 inch = 25.4 mm (NIST), to one decimal place. Ratios are short side first.
Sources, read 22 October 2026: Mpix prints, pixel guide; Shutterfly prints, pixel guide; Walgreens Photo prints, pixel guide, developer page.
How to use the tool
- Add a photo, or drop one on the box.
- Pick a print size, then drag and zoom the crop.
- Read how large it prints at 300 ppi and download a JPG or a PNG.
The shape of a 4 x 6
Walgreens Photo says the aspect ratio of a 4x6 print is 3:2. Written short side first, that is 2:3: the long side is one and a half times the short side.
Walgreens also sells a 4 x 5.3 True Digital print, a format which allows you to better match the dimensions of photos produced by most digital cameras. Mpix lists 4 x 5.3 too.
How many pixels a 4 x 6 needs
Mpix gives 400 x 600 as the minimum and 1000 x 1500 as optimal. Shutterfly lists two sizes for 4x6 prints: 640 x 480 as the minimum recommended resolution, and 1024 x 768. Walgreens gives 540 x 360 as its minimum. Worked out at 300 ppi, a 4 x 6 is 1200 x 1800 pixels.
Questions
Do the labs print a border?
All Walgreens photo prints are borderless. Mpix can add a 1/2 or 1/4 inch white border to most of its popular print sizes when you order.
Is it private?
Yes. The crop runs in your browser and nothing is uploaded. The HEIC decoder downloads once, when you first add a HEIC photo.
Why 300 ppi?
It is the labs' figure. Mpix recommends 250-300 DPI, Walgreens at least 200 PPI (its developer page says 300 DPI), and Shutterfly 300 dpi or higher for scans. The tool divides your pixels by 300.
Does the tool enlarge my photo?
No. The download is your crop at the photo's own pixels. As Walgreens notes, you cannot increase the resolution for images.
HEIC decoding uses heic-to and libheif, free software licensed under the GNU LGPL 3.0. They are included unmodified as a separate file, loaded only when you add a HEIC photo. The source code is at the links above.