How Many Pixels Do You Need to Print? (With Viewing Distance Chart)
One formula for any print size, a ready-made chart of common sizes, and why big posters can get away with less.
By Chris Bezuidenhout · · 6 min read
Whether a print comes out sharp or blurry depends mostly on one thing: does the image have enough pixels for the size you want? This guide gives you the formula, a chart of common sizes, and explains why a poster on the wall needs fewer pixels per inch than a photo in your hand.
The formula
Multiply the print size by the resolution you want. For inches:
For millimetres, convert to inches first by dividing by 25.4:
Do it for the width and the height. An 8 × 10 inch print at 300 PPI needs 8 × 300 = 2400 pixels across and 10 × 300 = 3000 pixels down. Your image needs to be at least that big in both directions.
Pixel chart for common print sizes
300 PPI is the standard for close-up viewing. 150 PPI is the usual minimum for large prints viewed from a distance.
| Print size | 300 PPI | 150 PPI |
|---|---|---|
| 4 × 6 in | 1200 × 1800 | 600 × 900 |
| 5 × 7 in | 1500 × 2100 | 750 × 1050 |
| 8 × 10 in | 2400 × 3000 | 1200 × 1500 |
| 11 × 14 in | 3300 × 4200 | 1650 × 2100 |
| 12 × 18 in | 3600 × 5400 | 1800 × 2700 |
| 16 × 20 in | 4800 × 6000 | 2400 × 3000 |
| 18 × 24 in | 5400 × 7200 | 2700 × 3600 |
| 24 × 36 in | 7200 × 10800 | 3600 × 5400 |
| A5 (148 × 210 mm) | 1748 × 2480 | 874 × 1240 |
| A4 (210 × 297 mm) | 2480 × 3508 | 1240 × 1754 |
| A3 (297 × 420 mm) | 3508 × 4961 | 1754 × 2480 |
| A2 (420 × 594 mm) | 4961 × 7016 | 2480 × 3508 |
| A1 (594 × 841 mm) | 7016 × 9933 | 3508 × 4967 |
Why viewing distance matters
Your eyes can only pick out so much detail, and the further away you stand, the less you can see. A person with normal eyesight can tell apart details about one arcminute apart (1/60th of a degree). Turn that into printing terms and you get a handy rule of thumb:
| Viewing distance | Most PPI the eye can see | Typical use |
|---|---|---|
| 30 cm (1 ft) | ≈ 290 | Photos, cards, books |
| 60 cm (2 ft) | ≈ 145 | Desk prints, small framed art |
| 1 m (3.3 ft) | ≈ 90 | Wall art, posters |
| 2 m (6.6 ft) | ≈ 45 | Large posters across a room |
| 3 m (10 ft) | ≈ 30 | Banners and signs |
This explains why 300 PPI became the standard: at reading distance, more than about 300 makes no visible difference. It also explains why a 24 × 36 inch poster at 150 PPI can look perfectly sharp on a wall.
One caution: people walk up close to art they like. For framed prints and anything you sell, it is safer to stay at 200 PPI or more, even if the maths says less would do.
Practical targets
- Photos, cards, flyers, books: 300 PPI.
- Framed prints and wall art: 200–300 PPI.
- Posters and canvases: 150–200 PPI. Canvas texture also hides some softness.
- Banners and signs: 50–100 PPI.
What if my image doesn’t have enough pixels?
You have a few options:
- Print smaller. Divide the pixel width by 300 to get the largest sharp width in inches.
- Accept a lower PPI if the print will be viewed from further away (see the chart above).
- Find the original file. Images saved from social media or messaging apps are often shrunk.
- Upscale it. AI upscalers can add pixels convincingly up to about 4×. See Can AI upscaling fix a low-resolution image?
More fixes are covered in How to fix a “low resolution” warning.
Check your image before you print
Upload a file, pick a print size and PrintCheck tells you in seconds if it will print sharp, needs upscaling, or is too small. Free, no sign-up, and your image is deleted straight after the check.
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