MakersMetric

DPI to Pixel & Dimension Converter

Interactive bidirectional dimensional calculator for engineering drawings, laser engraving, and additive manufacturing slicing resolution.

Common: 72 (Web), 300 (Print/Laser), 600 (High-Res CAD)
Pixels (px)
Millimeters (mm)
Inches (in)
Aspect Ratio: 1.78:1Total Pixels: 2.07 MP

Standard Dimension to Pixel Conversion Chart

Reference
Standard Size72 DPI (Web)150 DPI (Draft)300 DPI (High Res)600 DPI (Ultra)
1 Inch (25.4 mm)72 × 72 px150 × 150 px300 × 300 px600 × 600 px
100 × 100 mm (3.94")283 × 283 px591 × 591 px1,181 × 1,181 px2,362 × 2,362 px
4 × 6 Inch Print (101.6 × 152.4 mm)288 × 432 px600 × 900 px1,200 × 1,800 px2,400 × 3,600 px
US Letter 8.5 × 11" (215.9 × 279.4 mm)612 × 792 px1,275 × 1,650 px2,550 × 3,300 px5,100 × 6,600 px
A4 Sheet (210 × 297 mm)595 × 842 px1,240 × 1,754 px2,480 × 3,508 px4,960 × 7,016 px

Standard Resolution Guidelines

  • 72 DPI / PPI: Standard screen/web display resolution.
  • 150 DPI: Draft blueprints and large-format plotters.
  • 300 DPI: High-precision laser cutting, CNC raster carving, and technical print.
  • 600+ DPI: Ultra-fine photoetching, lithography, and micro-machining.

CAD & DPI FAQs

How do you calculate pixels from DPI and millimeters?

To convert millimeters to pixels, divide millimeters by 25.4 to get inches, then multiply by the DPI: Pixels = (Millimeters ÷ 25.4) × DPI. For example, 100mm at 300 DPI = (100 ÷ 25.4) × 300 = 1,181 pixels.

What DPI resolution should I use for laser engraving?

Optimal laser engraving resolution is typically 254 DPI to 318 DPI (0.1mm to 0.08mm line spacing). Setting DPI higher than your laser's optical focal spot diameter results in overlapping passes, prolonged job times, and burnt edges without adding detail.

What is the difference between DPI and PPI in CAD?

DPI (dots per inch) describes physical output dots created by a printer or laser head. PPI (pixels per inch) refers to the digital density of an image sensor or bitmap file. In digital vector rasterization, the two terms are functionally equivalent when setting export resolution.