DPI to PPI Converter

DPI to PPI — what it means for real-world sizing

In digital imaging, people often use DPI (dots per inch) and PPI (pixels per inch) interchangeably when they talk about resolution. For sizing math in raster workflows, the numeric value is the same — that’s why a simple dpi to ppi conversion is effectively 1:1 in practice. This page gives you a fast, accurate dpi to ppi converter online plus clear explanations, examples, and print-size helpers.

How to use the DPI → PPI converter

Enter a DPI value and the tool will return the equivalent PPI (same number), along with unit helpers for production work. Use the presets to move quickly between common print and scan settings, or type any value you need.

• Input: DPI value (type a custom number or tap a preset: 72, 100, 150, 200, 300, 600, 1200).
• Outputs:
  • PPI — identical to DPI for raster sizing.
  • px/mm = DPI ÷ 25.4   |   mm/px = 25.4 ÷ DPI   |   px/cm = DPI ÷ 2.54.
• Optional mini panel (print helper): enter pixel width and height to see physical print size at the chosen DPI (great for the “Pixels to print size calculator” use case).

Formula & how it works

In raster production, PPI = DPI for conversion purposes. Printers talk in dots per inch, designers and displays in pixels per inch — but when you map a digital image to a physical size, the same numeric resolution applies. That is why a DPI value can be treated as the equivalent PPI for layout math, print proofing, or scan settings. Once you know the resolution number, you can derive practical unit helpers that speed up everyday work.

Core:      PPI = DPI
Helpers:   px_per_mm = DPI / 25.4
           mm_per_px = 25.4 / DPI
           px_per_cm = DPI / 2.54

Here are compact numeric examples you can copy into specs or emails. Each row shows what one pixel measures in millimeters, plus the density in pixels per millimeter and per centimeter, at common settings:

Use these values to sanity-check artwork, define print specs without guesswork, and communicate clearly between design, prepress, and engineering teams. If you already know pixels and inches and want to solve for DPI directly, jump to the
DPI calculator.

Quick examples (badges)

Fast DPI → PPI references with millimeter factors. Copy the values you need for sizing specs, print briefs, or scan presets.

Reminder: px/mm = DPI ÷ 25.4  •
mm/px = 25.4 ÷ DPI

Conversion table — DPI → PPI with px/mm & mm/px

In raster sizing, PPI equals DPI. Use the factors below to jump between pixels and millimeters at common settings.

Reminder: px/mm = DPI ÷ 25.4 •
mm/px = 25.4 ÷ DPI

Pixel to print size chart — 300 DPI (width × height in pixels)

Quick reference for common photo and document sizes at 300 DPI (aka 300 DPI in pixels width and height).

Formula: pixels = inches × DPI  •
For A4 we use exact mm (210×297) → inches → pixels: ≈2480 × 3508.

Practical use-cases

DPI vs PPI — what’s the difference?

PPI (pixels per inch) describes pixel density in an image or on a display screen.
DPI (dots per inch) describes dot density used by printers and scanners.
For sizing math in raster workflows, you use the same numeric value—that’s why a simple
dpi to ppi conversion is effectively 1:1. In practice, treat a DPI number as the equivalent PPI when mapping pixels to a physical size.

FAQs — DPI to PPI

Related tools

Jump to these calculators to finish your sizing workflow—reverse mapping, DPI from pixels and inches, and physical-size converters.

More background on pixel density:
Wikipedia