What DPI do I need for a quality print?

300 DPI is the industry standard for professional quality prints intended for close viewing, such as A4 or A3 portrait prints. For larger format prints viewed at a distance (posters, exhibition prints, banners), 150 DPI is generally acceptable. Below 150 DPI this calculator flags the result as poor, and below roughly 100 DPI visible pixelation becomes likely on prints viewed at arm’s length. Screen and web use typically only requires 72–96 DPI.

How do I calculate DPI for a print?

Divide the pixel dimension of your image by the physical print dimension in inches. For example, a 3000 px wide image printed at 10 inches wide gives 300 DPI. If your print has different aspect ratios to your image, the limiting dimension (the one that gives the lower DPI) determines your actual print quality.

What is the maximum print size from a 24-megapixel image?

A 24-megapixel image (typically 6000 × 4000 px) can print at up to 20 × 13.3 inches (50.8 × 33.8 cm) at 300 DPI. At 150 DPI (acceptable for large prints viewed at arm's length or more) that increases to 40 × 26.7 inches (101.6 × 67.8 cm). Use this calculator to check any combination of resolution and print size.

Does the aspect ratio of my image matter for printing?

Yes. If your image aspect ratio does not match the print size you have chosen, either cropping or white borders will be needed. This calculator uses the more restrictive of the width and height DPI values to give the true achievable resolution at the specified print size, which highlights any aspect ratio mismatch.

Why does viewing distance change the DPI I need?

The further away a print is viewed, the less detail the eye can resolve, so a lower DPI looks just as sharp. A person with 20/20 vision resolves about one arcminute of detail, which gives a rule of thumb: the minimum PPI required ≈ 3438 ÷ viewing distance in inches. At a 30 cm (12 inch) reading distance that is roughly 290 PPI, but a poster viewed from 1 metre (about 39 inches) only needs around 87 PPI. Set the viewing distance in the advanced options and the calculator reports the minimum PPI for that distance and whether your achieved DPI meets it.

Print Resolution Calculator

How We Calculate This

How the calculation works

DPI is calculated by dividing the image pixel dimensions by the physical print dimensions in inches:

DPI = Image pixels ÷ Print size (inches)

The limiting dimension (lowest DPI of width or height) is used as the effective DPI.

Quality thresholds

300 DPI+: Excellent — professional print quality
200–299 DPI: Good — standard prints viewed at normal distance
150–199 DPI: Fair — large format or screen only
Below 150 DPI: Poor — pixelation likely

Maximum print sizes

Max size = Image pixels ÷ Target DPI

Calculated for both 300 DPI (professional) and the custom lower DPI threshold (default 150 DPI). Results are shown in your chosen unit — inches or centimetres.

Viewing distance

Sharpness is judged by the eye, not the printer. Using the 1-arcminute visual acuity rule:

Minimum PPI ≈ 3438 ÷ Viewing distance (inches)

Set the expected viewing distance in the advanced options to see the minimum PPI a print needs to look sharp at that distance, and whether your achieved DPI meets it.

Frequently Asked Questions

Related Calculators

Print Size Calculator

Find the maximum print size at a given DPI from your image resolution. Check if your photo is sharp enough for large prints. Free online photography calculator.

DPI Calculator

Calculate the DPI for any image size and print dimensions. Ensure your photos meet resolution requirements for sharp, professional prints. Free online calculator.

Megapixel to Print Calculator

Find maximum print sizes for your camera megapixel count at 150, 240 and 300 DPI. Check how large you can print with quality results. Free calculator.

Aspect Ratio Calculator

Convert between common photo aspect ratios and calculate crop dimensions. Avoid unexpected cropping when printing different format sizes. Free online calculator.

Crop Calculator

Calculate the effective megapixels remaining after cropping an image. See the resolution impact and equivalent focal length of any crop. Free online calculator.

Last updated: March 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.

Print Resolution Calculator — DPI, Quality & Max Print Size