Enter a print size and the closest distance anyone can get to it. Get the optical limit, the working specification, the full-size pixel dimensions and the scale to build the file at — instead of the single contradictory number every print shop quotes. Built by the team at Digital Polo for designers, print shops and brand teams.
Use the closest distance anyone can realistically get to the print, not the average or nominal one. It is the single decision that most affects the answer.
Capped by the substrate. The distance alone would allow 250 PPI, but the selected material — Not sure / general vinyl — tops out at 200 PPI of useful detail.
286.5 ÷ 2.5 ft. The finest detail a 20/20 eye can resolve at this distance. Beyond it, extra pixels cannot reach the retina as distinct detail.
461 megapixels — 1.7 GB uncompressed in 8-bit CMYK.
At 1:1 — full size, create the document at 120 in × 96 in and set the document resolution to 200 DPI. That yields 200 PPI at final size.
Effective resolution is pixel width divided by final print width. It is what actually prints, regardless of what the file claims.
The finest detail a 20/20 eye can resolve at that distance. Above it, extra pixels physically cannot reach the retina as distinct detail. A hard ceiling on usefulness, not a target.
Headroom for better-than-20/20 vision, for the person who walks up close, for hard edges that alias before photographs soften, and for the RIP's own dithering. Clamped between 15 and 300 PPI.
Mesh, fabric and canvas cap reproducible detail below whatever the file could carry. A 70/30 mesh banner is a third holes. No resolution recovers detail that falls into one.
Resolution requirement is angular, exactly as legibility is. A person with 20/20 vision resolves about one arcminute of detail; at one foot that subtends 0.0035 inches, so 286.5 distinguishable features fit into an inch. That is the whole origin of the 300 DPI convention, and it holds only at the distance it was derived for.
For a viewing distance D in feet, the optical limit in PPI is 286.5 ÷ D. The working specification doubles that and clamps the result between 15 and 300. Everything the calculator reports is PPI at final print size, which is the qualifier that causes most real-world failures — a 300 PPI image scaled to 400 per cent in a layout prints at 75.
The scale output solves a physical constraint, not a preference. The PDF format caps a page at 200 inches, Illustrator artboards at 227, and Photoshop PSDs at 30,000 pixels per side. Anything longer than about 16 feet must be built at scale. Final-size PPI equals document DPI multiplied by the scale factor, so a 1:10 document at 150 DPI delivers 15 PPI at full size — the standard billboard build.
What this tool does not do: it does not check colour, bleed, hems, pole pockets or grommet zones, and it does not know your printer's preferred file format or RIP. It assumes a 20/20 viewer in reasonable light. For the full treatment, read the guide on resolution for large format by print size and viewing distance.
Related reading: the print-ready file checklist, vector vs raster explained, CMYK vs RGB, and the sign letter height spec guide, which runs on the same arcminute maths. If you produce large format artwork commercially, we also run white-label design for print businesses and sign and banner shops.
It depends on how close someone can get to it, not on how big it is. The optical limit of a 20/20 eye is 286.5 divided by the viewing distance in feet, so a print viewed from 3 feet gains nothing above about 96 PPI and a billboard read from 100 feet gains nothing above about 3 PPI. Working specifications double the optical limit for safety and then clamp the result: 300 PPI within 2 feet, 150 to 200 PPI for a trade show banner or wall graphic, 100 to 150 PPI for a vehicle wrap, and 15 to 20 PPI at full size for a billboard.
Because the closest approach is what the print has to survive, and it is the number every published chart gets wrong. A trade show backwall has a nominal viewing distance of 10 feet, which would imply 30 PPI. Visitors stand at the counter 2 to 3 feet away reading the small print, which implies 150 to 200. Specify for the nominal distance and the graphic is technically defensible and looks cheap to the one person whose opinion matters.
A person with 20/20 vision resolves detail down to about one arcminute, one sixtieth of a degree. At one foot, one arcminute subtends 0.0035 inches, so 286.5 features fit in an inch. That is the entire origin of the 300 DPI convention — it is the density at which a 20/20 eye stops seeing a difference at arm's length. Divide 286.5 by the distance in feet and you have the limit at any other distance.
Five reasons, all legitimate. People get closer than planned. A meaningful share of adults see better than 20/20. Hard edges — type, logos, rules — alias visibly before photographs look soft. The RIP's dithering consumes some resolution to build tone. And files pick up losses through colour conversion and resaving. Doubling absorbs all of it. The result is then clamped at 300 PPI, since nothing is viewed closer than a foot, and at 15 PPI, below which the RIP's own interpolation is the limiting factor rather than your file.
Because the material frequently caps sharpness below whatever the file could deliver. A 70/30 mesh banner is perforated across roughly a third of its area, so around 20 to 40 PPI is all the detail it can carry. Dye sublimation lets dye migrate into the fabric fibres, softening every edge and making anything above 150 PPI wasted. Textured vinyl and canvas scatter fine detail. A UV-printed rigid board is the only large format substrate that reliably rewards 300 PPI.
The pixel density of an image after it has been scaled into the layout, and the only resolution figure that describes what will actually print. A 300 PPI photograph enlarged to 400 per cent has an effective resolution of 75 PPI — the metadata still says 300. Compute it as pixel width divided by final print width in inches, or enable the Effective PPI column in InDesign's Links panel, which is off by default and responsible for a great deal of reprinting.
Because the PDF format describes pages in units of 1/72 inch with a 14,400-unit maximum, which is 200 inches. Anything longer than 16 feet 8 inches cannot exist as a full-size PDF page at all. Illustrator artboards stop at 227 inches and Photoshop's PSD format at 30,000 pixels per side. Billboards and building wraps are therefore always built at scale — typically 1:10 — and the scale must be stated in the filename and the release note.
Not to satisfy the number. Resampling a 72 PPI file to 300 PPI produces a file that reports 300 PPI and contains 72 PPI of information. Upsampling is genuinely useful in one situation: RIPs interpolate badly, so resampling in Photoshop with Preserve Details 2.0 before you supply the file beats letting the RIP do it. The working limit is about 200 per cent. Beyond that, source the original at native size, re-shoot, or rebuild the element as vector.
No, and that is the escape hatch from the whole problem. Resolution only applies to raster content. Type, logos and flat shapes built as vector are resolution-independent — mathematically perfect at 15 PPI and at 3,000. A billboard built at 15 PPI has a headline with no resolution at all, because it is an outline. Spend the entire pixel budget on the photography and make everything else vector.
Digital Polo produces RIP-ready large format artwork on a flat monthly fee — correct scale, scaled bleed, outlined type, vector logos, Pantone references and every other print asset your brand needs.