The 300 DPI myth
The eye resolves detail down to roughly one arcminute. Convert that to a print and you need about 3438 ÷ viewing distance in inches pixels per inch to be at the limit of what anyone can see:
| Viewed from | Resolution at the eye's limit | Typical use |
|---|---|---|
| 12 in / 30 cm | 286 PPI | A print in the hand, a photo book |
| 18 in / 45 cm | 191 PPI | Desk print, album spread |
| 3 ft / 90 cm | 95 PPI | Framed print on a wall |
| 6 ft / 1.8 m | 48 PPI | Large living-room piece |
| 20 ft / 6 m | 14 PPI | Trade show banner |
300 DPI is not wrong — it is simply the answer for a print held at arm's reach, which is the only case where the number was ever measured. A three-metre print at 300 DPI would need 900 megapixels and nobody could tell it from 100.
People stand back from big prints. In practice the minimum comfortable viewing distance is roughly the print's diagonal — which means a well-made print is almost never resolution-limited. Print bigger than you think.
Standard sizes, and what they need
| At 300 DPI | Megapixels | At 200 DPI | Megapixels |
|---|
Assumes the print matches your file's aspect ratio. Cropping a 3:2 file to 8 × 10 throws away about 17% of the frame first — the aspect ratio calculator shows exactly how much.
Common questions
How big can I print a 12 MP photo?
About 13 × 10 inches at 300 DPI, 20 × 15 at 200 DPI, and comfortably 40 × 30 on a wall you view from two metres. Resolution requirements collapse with distance faster than most people expect.
DPI or PPI?
PPI is pixels per inch in the file. DPI is ink dots per inch on paper, and printers use several dots per pixel. Everyone says DPI, including this page — just know that a 2880 DPI printer is not asking for a 2880 PPI file.
Should I upscale before printing?
Most modern printer drivers resample for you and do it well. Upscale manually only if you are going far beyond the native size, and stop at roughly double the linear dimensions — past that, invented detail starts looking like invented detail.
Does the paper matter?
More than the last 50 PPI does. Matte and textured papers diffuse ink and cannot hold fine detail regardless of file resolution; gloss and baryta hold it all. If you are near the limit, a smoother paper buys you more than upscaling will.
Why does my 48 MP phone shot look soft printed large?
Small sensors gather less light, so the pipeline applies heavier noise reduction and sharpening. Both survive enlargement badly — noise reduction smears fine texture, sharpening leaves halos. Shooting raw and processing gently prints far better than the ready-made JPEG.
Related tools
Every megapixel your sensor actually has.
Lucid reads the resolutions your iPhone advertises — 12, 24 or 48 MP — instead of hardcoding a guess, and tells you the dimensions the file really came back with.