150 DPI in pixels
At 150 DPI an inch is 150 pixels and a centimetre is 59.1 pixels. An A4 page is 1240 × 1754 pixels and a US Letter page is 1275 × 1650.
150 DPI is a common minimum for posters and large prints seen from a step or two away, and a usual setting for scanning documents that only need to be read.
At 150 DPI the pixels of a print blend together, for someone with 20/20 vision, from about 22.9 inches (58 cm) away. Closer than that, an eye can pick out the pixel grid; further back, more resolution adds nothing you can see.
Paper and photo sizes at 150 DPI
| Size | Dimensions | Pixels at 150 DPI | Megapixels | Uncompressed |
|---|---|---|---|---|
| A0 | 841 × 1189 mm | 4967 × 7022 | 35 | 100 MB |
| A1 | 594 × 841 mm | 3508 × 4967 | 17 | 50 MB |
| A2 | 420 × 594 mm | 2480 × 3508 | 8.7 | 25 MB |
| A3 | 297 × 420 mm | 1754 × 2480 | 4.3 | 12 MB |
| A4 | 210 × 297 mm | 1240 × 1754 | 2.2 | 6.2 MB |
| A5 | 148 × 210 mm | 874 × 1240 | 1.1 | 3.1 MB |
| A6 | 105 × 148 mm | 620 × 874 | 0.54 | 1.6 MB |
| A7 | 74 × 105 mm | 437 × 620 | 0.27 | 794 KB |
| Letter | 8.5 × 11 in | 1275 × 1650 | 2.1 | 6 MB |
| Legal | 8.5 × 14 in | 1275 × 2100 | 2.7 | 7.7 MB |
| Tabloid | 11 × 17 in | 1650 × 2550 | 4.2 | 12 MB |
| Half Letter | 5.5 × 8.5 in | 825 × 1275 | 1.1 | 3 MB |
| 4 × 6 in | 4 × 6 in | 600 × 900 | 0.54 | 1.5 MB |
| 5 × 7 in | 5 × 7 in | 750 × 1050 | 0.79 | 2.3 MB |
| 8 × 10 in | 8 × 10 in | 1200 × 1500 | 1.8 | 5.1 MB |
| 11 × 14 in | 11 × 14 in | 1650 × 2100 | 3.5 | 9.9 MB |
| 16 × 20 in | 16 × 20 in | 2400 × 3000 | 7.2 | 21 MB |
| 12 × 12 in | 12 × 12 in | 1800 × 1800 | 3.2 | 9.3 MB |
| 12 × 18 in | 12 × 18 in | 1800 × 2700 | 4.9 | 14 MB |
| 18 × 24 in | 18 × 24 in | 2700 × 3600 | 9.7 | 28 MB |
| 24 × 36 in | 24 × 36 in | 3600 × 5400 | 19 | 56 MB |
| Business card | 2 × 3.5 in | 300 × 525 | 0.16 | 461 KB |
Lengths at 150 DPI
| Inches | Pixels |
|---|---|
| 0.25 in | 38 |
| 0.5 in | 75 |
| 0.75 in | 113 |
| 1 in | 150 |
| 1.5 in | 225 |
| 2 in | 300 |
| 2.5 in | 375 |
| 3 in | 450 |
| 3.5 in | 525 |
| 4 in | 600 |
| 5 in | 750 |
| 6 in | 900 |
| Centimetres | Pixels |
|---|---|
| 0.5 cm | 30 |
| 1 cm | 59 |
| 1.5 cm | 89 |
| 2 cm | 118 |
| 2.5 cm | 148 |
| 3 cm | 177 |
| 3.5 cm | 207 |
| 4 cm | 236 |
| 4.5 cm | 266 |
| 5 cm | 295 |
| 6 cm | 354 |
| 7 cm | 413 |
| Millimetres | Pixels |
|---|---|
| 1 mm | 6 |
| 2 mm | 12 |
| 3 mm | 18 |
| 5 mm | 30 |
| 10 mm | 59 |
| 15 mm | 89 |
| 20 mm | 118 |
| 25 mm | 148 |
| 30 mm | 177 |
| 35 mm | 207 |
| 40 mm | 236 |
| 45 mm | 266 |
Changing an image to 150 DPI
The DPI stored in an image file is a label that says how large to print it. Changing the label to 150 without resampling keeps every pixel and only changes the print size: a 3000 × 2000 pixel photo becomes 20 × 13.33 inches. Resampling changes the number of pixels instead, and making an image larger that way does not add detail.