MM to PX Converter
Result: 3.78px
Calculation based on the CSS reference pixel of 3.7795275591 pixels per inch (96px = 25.4mm).
How to Use the Converter?
Select the input field labeled "Millimeters"
Change the number in an input field
Converter will automatically convert
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MM to PX: How the Conversion Works
Converting millimeters to pixels lets you translate a metric, physical measurement into digital design units. Since the CSS standard fixes 1 inch at 96px, and 1 inch equals 25.4mm, each millimeter works out to about 3.78 pixels.
This conversion is common when working from print specifications (metric measurements are standard in most countries outside the US) and needing to lay them out accurately in a web page, digital mockup, or design tool.
For example, a 100mm × 150mm postcard equals roughly 378px × 567px at 96 DPI. A 20mm icon equals about 76px.
Use the converter above to instantly switch between millimeters and pixels for any value.
Common MM to PX Conversions
2.65mm
10px
5mm
19px
10mm
38px
25.4mm
96px
50mm
189px
100mm
378px
150mm
567px
210mm
794px
Quick Conversion Tips
Converting MM to PX
Multiply the millimeter value by 3.7795275591. Example: 100mm × 3.78 ≈ 378px
Converting PX to MM
Divide the pixel value by 3.7795275591. Example: 378px ÷ 3.78 ≈ 100mm
Learn More About CSS Units
PX vs Inches, MM, and CM
Learn how pixels relate to inches, millimeters, and centimeters using the CSS 96 DPI standard, and avoid the most common print-design conversion mistake.
Read our comprehensive guide →Related Converters
Frequently Asked Questions
How many px is 1mm?
1 millimeter equals approximately 3.78 pixels, based on the CSS standard of 96 pixels per inch.
How do I convert mm to px?
Multiply the millimeter value by 3.7795275591. For example, 50mm × 3.78 ≈ 189px. Use the converter above for instant results.
How do I convert px to mm?
Divide the pixel value by 3.7795275591. For example, 189px ÷ 3.78 ≈ 50mm.
Why use mm instead of inches for this conversion?
Millimeters are the standard unit of length in the metric system used by most countries, making mm-to-px conversion useful for international print and design specifications.
Does this conversion account for high-resolution (Retina) screens?
No, this uses the CSS reference pixel (96 DPI), which is a logical unit independent of a screen's actual physical pixel density. High-DPI screens render CSS pixels using multiple physical pixels internally.