How many millimeters equal 1 inch?

25.4 mm = 1 inch exactly (by international standard since 1959). So conversely, 1 mm ≈ 0.0394 inches.

I have a European design spec of 15 mm margins. What's that in inches?

15 mm × 0.0394 ≈ 0.59 inches. Close to 0.5 inches (the standard US margin width).

What's the easiest way to remember this conversion?

Remember: 25.4 mm = 1 inch. You can divide any mm value by 25.4 to get inches, or multiply by 0.0394 for quick conversions.

Why is the conversion exactly 25.4 and not a rounder number?

By international agreement (1959), the inch was redefined to equal exactly 25.4 mm. This standardized imperial-metric conversion globally.

Millimeter to Inch Converter

Enter a value to instantly convert between typography units.

From

Precision4 dp

1 Millimeter = 0.0394 Inch

Key Formulas

Point → Pica

pc = pt × 0.0833333

Point → Inch

in = pt × 0.0138889

Pica → Inch

in = pc × 0.166667

Millimeters are metric measurements; inches are imperial. The exact conversion is 1 mm = 0.03937 inches (or 1 inch = 25.4 mm). This is essential when working with international clients or adapting metric specifications to US/UK print standards.

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

Frequently Asked Questions

Real-World Examples

10 mm (1 cm) ≈ 0.39 inches. Small metric measurement converts to roughly a third of an inch.

10 mm = 0.3937 in

25.4 mm = exactly 1 inch. The precise conversion point between metric and imperial.

25.4 mm = 1 in

50 mm (5 cm) ≈ 1.97 inches. Standard metric margin size equals about 2 inches in imperial.

50 mm = 1.9685 in

210 mm (A4 height) ≈ 8.27 inches. International paper size translates to US measurements.

210 mm = 8.2677 in

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

Millimeter to Inch Converter

Key Formulas

Frequently Asked Questions

Real-World Examples

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