How many pixels do you need for a 4×6, 5×7 or A4 print?
The pixel dimensions for sharp prints at common photo sizes, what 300 and 150 DPI mean in practice, and what to do when your photo is too small for the print.
Published
Tools for this job: Change Image DPI · Crop Image · Resize Image
Before ordering prints or sending a file to a print shop, it helps to know whether the photo has enough pixels for the size you want. The answer comes from simple multiplication: the print size in inches times the print resolution in dots per inch.
Pixels for common print sizes
| Print size | At 300 DPI | At 150 DPI |
|---|---|---|
| 4 × 6 in | 1200 × 1800 | 600 × 900 |
| 10 × 15 cm | 1181 × 1772 | 591 × 886 |
| 5 × 7 in | 1500 × 2100 | 750 × 1050 |
| 13 × 18 cm | 1535 × 2126 | 768 × 1063 |
| A5 | 1748 × 2480 | 874 × 1240 |
| 8 × 10 in | 2400 × 3000 | 1200 × 1500 |
| A4 | 2480 × 3508 | 1240 × 1754 |
300 DPI is the usual target for photos held in the hand. 150 DPI is acceptable for larger prints seen from further away, such as a poster on a wall. Any modern phone photo, at 3000 pixels or more on the long side, comfortably covers everything up to A4 at 300 DPI.
Check your photo
Look at the image's pixel dimensions in your computer's file properties, or open it in Change Image DPI, which shows the pixel size and the print size at any density you choose. Type a printed width in millimetres and it tells you the resulting DPI. If that is 300 or close to it, the print will be sharp.
The shape matters too
Phone photos are usually 4:3, while 4 × 6 prints are 3:2 and 5 × 7 prints are 7:5. If the shapes differ, the lab either crops your photo or leaves white bars. To control which part is cut, crop it yourself before ordering in Crop Image: the 3:2 preset matches 4 × 6 and 10 × 15 cm exactly, and Free with typed dimensions handles the rest.
When the photo is too small
- Print smaller. An image that is 1200 pixels wide is excellent at 4 × 6 and disappointing at A4.
- Accept lower DPI for big prints. 200 DPI is usually fine for 8 × 10 viewed at arm's length.
- Find the original. Photos saved from messaging apps and social networks are heavily reduced. Ask the sender for the original file.
- Do not rely on enlarging. Resizing a small image up in Resize Image makes it bigger but cannot add detail; edges soften.
Ordering prints online
Most photo labs warn you when an image is too small for the size you choose, usually with a low-quality icon on the order page. Take that warning seriously for anything you plan to frame. Labs also offer “crop to fit” or “fit with border”; choose deliberately rather than accepting the default, or crop beforehand so there is nothing for the lab to decide.
The DPI number in the file
Some labs and forms complain that a photo is “72 DPI”. That figure is only a label stored in the file. What matters is the pixel count. Change Image DPI can rewrite the label to 300 without touching any pixels, which satisfies picky upload forms. The fuller explanation is in what DPI means for printing.