300 DPI in pixels
At 300 DPI an inch is 300 pixels and a centimetre is 118.1 pixels. An A4 page is 2480 × 3508 pixels and a US Letter page is 2550 × 3300.
300 DPI is the standard for print that is held in the hand: books, magazines, photo prints, business cards and flyers. At reading distance the eye can no longer pick out the pixels.
At 300 DPI the pixels of a print blend together, for someone with 20/20 vision, from about 11.5 inches (29 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 300 DPI
| Size | Dimensions | Pixels at 300 DPI | Megapixels | Uncompressed |
|---|---|---|---|---|
| A0 | 841 × 1189 mm | 9933 × 14043 | 139 | 399 MB |
| A1 | 594 × 841 mm | 7016 × 9933 | 70 | 199 MB |
| A2 | 420 × 594 mm | 4961 × 7016 | 35 | 100 MB |
| A3 | 297 × 420 mm | 3508 × 4961 | 17 | 50 MB |
| A4 | 210 × 297 mm | 2480 × 3508 | 8.7 | 25 MB |
| A5 | 148 × 210 mm | 1748 × 2480 | 4.3 | 12 MB |
| A6 | 105 × 148 mm | 1240 × 1748 | 2.2 | 6.2 MB |
| A7 | 74 × 105 mm | 874 × 1240 | 1.1 | 3.1 MB |
| Letter | 8.5 × 11 in | 2550 × 3300 | 8.4 | 24 MB |
| Legal | 8.5 × 14 in | 2550 × 4200 | 11 | 31 MB |
| Tabloid | 11 × 17 in | 3300 × 5100 | 17 | 48 MB |
| Half Letter | 5.5 × 8.5 in | 1650 × 2550 | 4.2 | 12 MB |
| 4 × 6 in | 4 × 6 in | 1200 × 1800 | 2.2 | 6.2 MB |
| 5 × 7 in | 5 × 7 in | 1500 × 2100 | 3.2 | 9 MB |
| 8 × 10 in | 8 × 10 in | 2400 × 3000 | 7.2 | 21 MB |
| 11 × 14 in | 11 × 14 in | 3300 × 4200 | 14 | 40 MB |
| 16 × 20 in | 16 × 20 in | 4800 × 6000 | 29 | 82 MB |
| 12 × 12 in | 12 × 12 in | 3600 × 3600 | 13 | 37 MB |
| 12 × 18 in | 12 × 18 in | 3600 × 5400 | 19 | 56 MB |
| 18 × 24 in | 18 × 24 in | 5400 × 7200 | 39 | 111 MB |
| 24 × 36 in | 24 × 36 in | 7200 × 10800 | 78 | 222 MB |
| Business card | 2 × 3.5 in | 600 × 1050 | 0.63 | 1.8 MB |
Lengths at 300 DPI
| Inches | Pixels |
|---|---|
| 0.25 in | 75 |
| 0.5 in | 150 |
| 0.75 in | 225 |
| 1 in | 300 |
| 1.5 in | 450 |
| 2 in | 600 |
| 2.5 in | 750 |
| 3 in | 900 |
| 3.5 in | 1,050 |
| 4 in | 1,200 |
| 5 in | 1,500 |
| 6 in | 1,800 |
| Centimetres | Pixels |
|---|---|
| 0.5 cm | 59 |
| 1 cm | 118 |
| 1.5 cm | 177 |
| 2 cm | 236 |
| 2.5 cm | 295 |
| 3 cm | 354 |
| 3.5 cm | 413 |
| 4 cm | 472 |
| 4.5 cm | 531 |
| 5 cm | 591 |
| 6 cm | 709 |
| 7 cm | 827 |
| Millimetres | Pixels |
|---|---|
| 1 mm | 12 |
| 2 mm | 24 |
| 3 mm | 35 |
| 5 mm | 59 |
| 10 mm | 118 |
| 15 mm | 177 |
| 20 mm | 236 |
| 25 mm | 295 |
| 30 mm | 354 |
| 35 mm | 413 |
| 40 mm | 472 |
| 45 mm | 531 |
Changing an image to 300 DPI
The DPI stored in an image file is a label that says how large to print it. Changing the label to 300 without resampling keeps every pixel and only changes the print size: a 3000 × 2000 pixel photo becomes 10 × 6.67 inches. Resampling changes the number of pixels instead, and making an image larger that way does not add detail.