Why is 1 millimeter ≈ 3.78 pixels?

Because 25.4 mm = 1 inch and 1 inch = 96 px (web standard). So 96 ÷ 25.4 ≈ 3.78 px per mm.

My metric spec says 20 mm padding. What's that in pixels for CSS?

20 mm × 3.78 ≈ 75.6 px. Use padding: 76px in your CSS, or better, use em/rem for responsive scaling.

I'm converting an international design from metric to web pixels. Any tips?

Use this converter for rough pixel estimates, but consider using em or rem units in CSS instead. They scale better across devices than fixed pixel values.

Does the conversion change on different monitors?

In CSS, no. Browsers maintain 96 DPI conversion regardless of physical monitor DPI. In image editing, DPI varies by tool and display, so always verify your output settings.

Millimeter to Pixel Converter

Enter a value to instantly convert between typography units.

From

Precision4 dp

1 Millimeter = 3.7795 Pixel

Key Formulas

Point → Pica

pc = pt × 0.0833333

Point → Inch

in = pt × 0.0138889

Pica → Inch

in = pc × 0.166667

Millimeters are metric fixed measurements; pixels are screen units. At standard web DPI (96 pixels per inch), 1 millimeter equals approximately 3.78 pixels. This conversion is critical for international teams translating metric design specifications to web-based responsive layouts.

Last reviewed: 2026-06-11 · see our methodology

Frequently Asked Questions

Real-World Examples

5 mm ≈ 19 px. Small metric spacing (0.5 cm) translates to about 19-pixel padding in web CSS.

5 mm = 18.898 px

10 mm (1 cm) ≈ 38 px. Standard metric margin converts to reasonable web spacing.

10 mm = 37.796 px

25.4 mm (1 inch) = 96 px exactly. Reference point for all web measurements at 96 DPI.

25.4 mm = 96 px

50 mm (5 cm) ≈ 189 px. Large metric margin equals substantial web spacing for major layout sections.

50 mm = 188.976 px

points to picas points to type inches picas to type inches points to mm pixels to points ems to rems

Millimeter to Pixel Converter

Key Formulas

Frequently Asked Questions

Real-World Examples

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