Sizes
| Size (in) | Size (cm) | Ratio | Mpix | Shutterfly | Walgreens |
|---|---|---|---|---|---|
| 11 x 14 | 27.9 x 35.6 | 11:14 | Print. 1100 x 1400 minimum, 2750 x 3500 optimal. | Print, Poster. 2000 x 1600 recommended. | Poster. 1008 x 792 minimum. |
| 12 x 18 | 30.5 x 45.7 | 2:3 | Print, Poster. 1200 x 1800 minimum, 3000 x 4500 optimal. | Not listed. | Poster. 2682 x 1788 minimum. |
| 16 x 20 | 40.6 x 50.8 | 4:5 | Print. 1600 x 2000 minimum, 4000 x 5000 optimal. | Print, Poster. 2000 x 1600 recommended. | Poster. 2980 x 2384 minimum. |
| 16 x 24 | 40.6 x 61 | 2:3 | Print, Poster. 1600 x 2400 minimum, 4000 x 6000 optimal. | Not listed. | Not listed. |
| 18 x 24 | 45.7 x 61 | 3:4 | Print. No pixel size published. | Not listed. | Named on its posters page. No pixel size published. |
| 20 x 30 | 50.8 x 76.2 | 2:3 | Print, Poster. 2000 x 3000 minimum, 5000 x 7500 optimal. | Print, Poster. 2000 x 1600 recommended. | Poster. 4470 x 2980 minimum. |
| 24 x 36 | 61 x 91.4 | 2:3 | Print, Poster. 2400 x 3600 minimum, 6000 x 9000 optimal. | Not listed. | Poster. 5400 x 3600 minimum. |
| 36 x 48 | 91.4 x 121.9 | 3:4 | Poster. No pixel size published. | Not listed. | Not listed. |
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, posters; Shutterfly prints, posters, pixel guide; Walgreens Photo posters, pixel guide, posters page, mail delivery, 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.
What each lab lists
Mpix prints posters on 30 lb. poster paper with a 1/8 inch white border on all sides. Shutterfly also lists 8 x 8, 8 x 10 and 12 x 12. Walgreens sends 12 x 18 by mail only, and its posters page names 18 x 24.
Questions
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.
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.