DPI / PPI Calculator

Calculate the DPI (dots per inch) of an image at a given print size, or the pixel dimensions required for a target DPI.

Inputs

Mode

Image width (pixels)

Image height (pixels)

Print width (inches)

Print height (inches)

Target DPI

Results

DPI vs PPI

PPI (pixels per inch) describes the pixel density of the digital image when mapped to a physical size. DPI is often used interchangeably in photography print workflows. For a sharp print viewed up close, aim for about 300 PPI. Large wall prints viewed from farther away can look excellent at 150–200 PPI.

Formula

DPI = pixels ÷ print size in inches

Pixels needed = print inches × target DPI

Example

A 6000×4000 px image printed 20 inches wide → 6000/20 = 300 DPI on the long edge.

FAQ

Does upscaling help?

Moderate upscaling with modern AI tools can help, but it cannot invent true optical detail. Capture more pixels or print smaller when quality is critical.

What about cm?

Convert cm to inches (÷ 2.54) first, or use the print size calculator which shows both.

Preparing files for labs

Labs often request a specific PPI and color space. Compute required pixel dimensions, then resize with a high-quality algorithm only when necessary. Avoid upscaling small web files for large canvases; shoot or scan with enough pixels instead.