How many pixels do I need for a 24 x 36 poster?
Choose a realistic PPI for the intended viewing distance, then multiply 24 and 36 inches by that PPI. A closer-viewed poster needs more pixels than signage viewed from across a room.
Pixels required for a 24 × 36 inch poster
| Target PPI | Required pixels | Approx. megapixels |
|---|---|---|
| 100 | 2400 × 3600 | 8.6 MP |
| 150 | 3600 × 5400 | 19.4 MP |
| 200 | 4800 × 7200 | 34.6 MP |
| 240 | 5760 × 8640 | 49.8 MP |
| 300 | 7200 × 10800 | 77.8 MP |
300 PPI requires 7200 × 10800 px, but that does not mean every 24 × 36 poster needs 300 PPI. Viewing distance, image detail and the output provider's process matter. Use the provider requirement when it exists.
Use the numbers from your actual job
The guide explains the decision; the linked calculator gives you the value for your own file or production assumptions.
The required pixels depend on the PPI target
For a 24 × 36 inch poster, 150 PPI requires 3600 × 5400 px, 200 PPI requires 4800 × 7200 px, and 300 PPI requires 7200 × 10800 px. Multiplying physical inches by PPI gives the raster requirement directly.
300 PPI is not automatically required for a poster
Large prints are often viewed farther away than a handheld photo. Subject detail, viewing distance, substrate and output process can make a lower effective PPI practical. Use the provider’s published requirement whenever it exists.
Cropping can reduce the pixels available
24 × 36 is a 3:2 ratio. If the source image has another ratio, crop first conceptually and calculate PPI from the pixels that remain after the crop.
Do not confuse printer DPI with image PPI
A printer can advertise a high device DPI while the supplied image still has too few source pixels. For file preparation, compare source pixels with final physical inches.
Practical answer
Choose a realistic PPI for the intended viewing distance, then multiply 24 and 36 inches by that PPI. A closer-viewed poster needs more pixels than signage viewed from across a room.
When the decision affects a paid print run, book upload, client order or expensive material, keep the calculation with the job notes and verify any external specification again immediately before production.