PX to MM Converter

PX → MM Converter

Pixels you want to express in millimeters.
Millimeters (mm): —
Inches (reference): —
CSS Snippet:
.element { width: 10mm; }
💡 Quick Presets
📊 Quick Reference (your px → mm)
CSS Standard
@96 px/in → mm = px × 25.4 / 96 (≈ × 0.264583)
—
Print-aware (mm at DPI)
DPI 300: — mm
DPI 240: — mm
DPI 150: — mm
DPI 72: — mm
Live Preview
This element applies the computed value in mm to the selected property.

PX to MM Converter

In digital design and printing, you’ll often need to convert between screen-based units like pixels (PX) and physical units like millimeters (MM). While pixels measure resolution on digital screens, millimeters are used in real-world printing and physical sizing. A PX to MM Converter bridges the gap between these two measurement systems, helping designers, developers, and printers ensure accurate dimensions across both media.

This is especially important when designing graphics, UI layouts, or print-ready files where you must know how many millimeters a pixel value translates into at a given DPI (dots per inch).

Why Convert Pixels to Millimeters?

  • Print accuracy: Printing requires physical dimensions (mm, cm, inches), not pixels.
  • Cross-platform design: Helps ensure a design looks the same in both digital and physical forms.
  • Better scaling: Prevents distortion when resizing between screen and print.
  • Professional workflows: Essential in photography, web-to-print designs, and UI mockups.

The Formula for PX to MM

The conversion depends on the DPI (dots per inch) value of the image or screen.

Formula:

Millimeters = (Pixels ÷ DPI) × 25.4

Example:
 If an image is 300px wide at 96 DPI:

(300 ÷ 96) × 25.4 = 79.375 mm

So, 300px = 79.38 mm (rounded).

When to Use PX to MM Conversion

  1. Graphic Design for Print – Posters, flyers, or business cards created digitally but printed physically.
  2. UI/UX & App Design – Ensuring touch elements are sized correctly for physical usability.
  3. 3D Printing & CAD – Translating on-screen dimensions into real-world millimeters.
  4. Photography & Printing – Preparing high-resolution images for physical prints.

Benefits of Using a PX to MM Converter

  • Quick and accurate: No manual math needed.
  • Supports multiple DPIs: You can adjust based on 72 DPI, 96 DPI, or print-standard 300 DPI.
  • Reduces mistakes: Ensures accurate physical sizing.
  • Time-saving: Great for designers and developers who need fast conversions.

FAQs 

Why does DPI matter when converting PX to MM?

Because DPI (dots per inch) determines how many pixels fit in one inch. Without it, pixels cannot be directly translated into physical units like mm.

What is the standard DPI to use?
For screens, 72 or 96 DPI is common. For printing, 300 DPI is the industry standard.

Can I use PX to MM conversion for web design?
Not directly, since web design is resolution-independent. However, it’s useful when matching digital graphics with print requirements.

Do different screens have different pixel-to-mm values?
Yes. A pixel on a smartphone screen may physically be smaller than on a desktop monitor. That’s why DPI (or PPI) is always required.

Is converting PX to CM the same as PX to MM?
Yes, it’s similar. Since 10mm = 1cm, once you get the value in mm, you can divide by 10 to get centimeters.