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Large-Format Printing Resolution: How Much DPI You Really Need

By the Resly AI team · Updated 5 October 2026

The short answer

Far less than 300. The eye resolves about 287 pixels per inch at 1 foot, 96 at 3 feet and 29 at 10 feet, so posters are usually printed at 150 DPI and banners at 100 or less. The rule: required DPI ≈ 3,438 ÷ viewing distance in inches. Add margin for people who walk up close.

Resolution by viewing distance

Good eyesight tells apart details about one arcminute apart. Turn that into pixels per inch at a distance and you get the rule above. Past that resolution, extra pixels are invisible from where people stand.

Pixels per inch the eye can resolve at each viewing distance
1 ftDPI the eye resolves: 287Typical print: Photo prints, books, cards
3 ftDPI the eye resolves: 96Typical print: Posters, framed prints, menus
6 ftDPI the eye resolves: 48Typical print: Pull-up banners, trade show graphics
10 ftDPI the eye resolves: 29Typical print: Hanging banners, shop windows
20 ftDPI the eye resolves: 14Typical print: Building banners, large signs
50 ftDPI the eye resolves: 6Typical print: Billboards, building wraps

3,438 ÷ distance in inches, rounded. Real jobs add margin, because someone always walks right up to the banner.

Pixels for common sizes

Pixels needed for common large-format sizes
18×24 in posterUsually printed at: 150 DPIPixels needed: 2,700 × 3,600 px
24×36 in posterUsually printed at: 150 DPIPixels needed: 3,600 × 5,400 px
33×81 in pull-up bannerUsually printed at: 100 DPIPixels needed: 3,300 × 8,100 px
3×6 ft vinyl bannerUsually printed at: 100 DPIPixels needed: 3,600 × 7,200 px
4×8 ft vinyl bannerUsually printed at: 75 DPIPixels needed: 3,600 × 7,200 px

Common shop defaults, not rules. Check what your printer or RIP expects.

When the customer file is still too small

  • Work out the effective DPI first: the file's pixels divided by the print's inches. A customer's 2,000-pixel-wide logo across a 6 ft banner is 28 DPI: fine from 10 feet, soft up close.
  • Ask for the original or a vector before anything else. Logos and type almost always exist as vectors somewhere; see upscaling a logo for a banner.
  • Upscale photos to the size they'll print at. Resly delivers up to 16 megapixels, which across a 3×6 ft banner works out at about 79 DPI, fine from a few metres away.
  • Don't let the RIP enlarge it. Enlarging in the RIP adds pixels without adding detail; a proper upscale rebuilds the detail first.
A colour slide of a family outside a clay house in Sikkim, upscaledA colour slide of a family outside a clay house in Sikkim, before upscalingBeforeAfter
A 1024-pixel scan of a colour slide, upscaled by Resly. Library of Congress, no known restrictions.

Upscale a file for large format

Upload it and type the print size. You see the price before you pay. Print shops upscaling customer files every week use Resly Studio, with credits and batches.

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Questions

What DPI is needed for a banner?

Usually 100 DPI at full size, and less for big banners seen from far away. The eye resolves only about 29 pixels per inch at 10 feet, so 300 DPI is wasted on a banner.

How do you calculate DPI from viewing distance?

Divide 3,438 by the viewing distance in inches. At 3 feet (36 inches) that is about 96 DPI; at 10 feet, about 29. Add some margin for people who walk up close.

Is 150 DPI good enough for a poster?

Yes, for a poster seen from a step or two away. 300 DPI matters for prints held in the hand.

What resolution do billboards use?

Very low, often 10–20 DPI at full size, because they are seen from 50 feet or more, where the eye resolves only about 6 pixels per inch.