PrintSize: DPI Calculator

PrintSize answers the two questions you have before sending a file to print. How good will this look at the size I want? And how big can I go before it falls apart?

It works both directions. Give it the pixel dimensions and the size you want printed, and it returns the effective PPI with a quality grade. Give it the pixel dimensions and a target PPI, and it returns the largest print you can make at that quality.

WHAT YOU CAN DO
- Enter the pixel width and height of your file, from a camera, a scan or an export.
- Mode one: enter the size you want printed and read the PPI you will actually get.
- Mode two: enter a target PPI and read the maximum size you can print at it.
- Work in inches, centimetres or millimetres.
- Pick from twelve common sizes: 4x6, 5x7, 8x10, 8.5x11 Letter, 11x14, 11x17 Tabloid, 16x20, 20x30, 24x36, and A4, A3 and A2.
- Read the grade for the PPI you get in mode one: museum at 360 PPI and above, fine art from 300, standard from 200, and wall art below that.
- Tap a preset and its size fills in, converted to the unit you are working in.
- Watch the answer update as you type.

ABOUT THE EFFECTIVE PPI
When the aspect ratio of your file does not match the aspect ratio of the paper, the two axes give different PPI figures. PrintSize reports the lower of the two as the effective PPI, because the limiting axis is what you will see. It is the honest number, not the flattering one.

A WORKED EXAMPLE
A 3000 by 2000 pixel file printed at 12 by 8 inches gives 250 PPI, graded standard. Ask for 300 PPI instead, and the largest print you can make is 10 by 6.67 inches.

WHO IT IS FOR
Photographers ordering prints, designers checking a client file before it goes to press, anyone framing something for a wall, and anyone who has been told a file is too low resolution and wants to know exactly how low.

PRIVACY
No accounts, no analytics, no network requests. Nothing you type leaves the device.