What DPI do you need for printing?
The standard answer is 300 DPI, and for most photo printing it's correct. But DPI isn't a fixed property of an image — it's pixels divided by print size. The same file can be razor-sharp on a business card and blurry on a poster. Here's how to know which you've got.
DPI is pixels ÷ inches
Effective print resolution is simply your image's pixel dimensions divided by the printed size. A 3000 × 2400 px photo printed at 10 × 8 inches gives 300 DPI. Print that same file at 20 × 16 inches and it drops to 150 DPI — same pixels, twice the size, half the resolution.
That's the key insight: there's no DPI 'in' a JPEG until you decide how big to print it. The metadata DPI tag in a file means nothing for quality; only pixels and final size do.
The only formula you need
Effective DPI = pixel width ÷ print width (inches). If that number clears your target, the image prints sharp. The DPI calculator does it both ways — check a size, or find the largest sharp size for any file.
How much resolution is actually enough
300 DPI is the default for photographic print viewed in the hand — books, magazines, brochures, cards. But the right target scales with how far away the piece is seen:
| Output | Viewing distance | Target DPI |
|---|---|---|
| Business card, book, magazine | In hand (~30 cm) | 300 DPI |
| Brochure photography | Arm's length | 250–300 DPI |
| A2 / A1 poster | ~1 m | 150–200 DPI |
| Trade-show banner | 2–3 m | 100–150 DPI |
| Billboard | Many metres | 20–50 DPI |
Why you can get away with less on big prints
Your eye resolves less detail the further away something is. A billboard at 30 DPI looks crisp from across a street because you physically cannot see its individual dots from there. Demanding 300 DPI on a banner would mean an enormous file for no visible benefit.
The mistake runs the other way too: scaling a small web image up to poster size in Photoshop adds pixels by interpolation but no real detail, so it stays soft. Resolution comes from the original capture — you can throw pixels away cleanly, but you can't invent them.
DPI vs PPI vs LPI
Three similar acronyms cause endless confusion:
- PPI (pixels per inch) — describes your digital image.
- DPI (dots per inch) — describes ink dots a printer lays down. In everyday use, designers treat DPI and PPI as the same target number.
- LPI (lines per inch) — the halftone screen frequency, a press setting. A rough guide is that you want image PPI around 1.5–2× the LPI.
For day-to-day file prep, aim your image resolution at the targets above and let the printer handle LPI.
Frequently asked questions
Is 300 DPI always required?
No. 300 DPI is right for things viewed up close. Posters and banners viewed from metres away look perfect at 100–200 DPI, and forcing 300 just bloats the file.
Can I increase a photo's DPI in Photoshop?
Changing the DPI number without resampling just relabels the same pixels. Resampling up adds interpolated pixels but no true detail, so it won't make a low-res image genuinely sharp. Start from the highest-resolution original you have.
What DPI for line art or logos?
Pure black-and-white line art benefits from much higher resolution — 600 to 1200 DPI — because hard edges show jaggedness that photos hide. Better still, use vector artwork, which is resolution-independent.
My image is 72 DPI — is it unusable for print?
Not necessarily. 72 DPI is just a label. If the pixel dimensions are large enough for your print size (pixels ÷ inches ≥ your target), it prints fine. Check the pixels, not the DPI tag.
300 is a default, not a law
The number that matters isn't 300 — it's pixels divided by print size. Once that clicks, you stop over-sizing files for billboards and under-sizing them for business cards. Reviewed June 14, 2026.