Inch to Millimeter Converter

Enter a value to calculate the result instantly and free of charge.

in
25.4mm

1 in = 25.4 mm

Conversion summary

1 in = 25.4 mm

Formula
Millimeter = Inch × 25.4
Category
Length
Units
inmm

How do you convert inch to millimeter?

To convert inch to millimeter, multiply the inch value by 25.4. One in is equal to 25.4 mm.

Conversion formula

Millimeter = Inch × 25.4

Inch to Millimeter conversion table

InchMillimeter
0.026 in0.6604 mm
0.0394 in1.00076 mm
0.1969 in5.00126 mm
0.3937 in9.99998 mm
1 in25.4 mm
1.9685 in49.9999 mm

What is Inch?

The inch is a short unit of length used in imperial and United States customary systems. One inch is exactly 2.54 centimeters.

Short history of Inch

The inch developed from older local measures tied to the body. The modern international inch has been fixed at exactly 25.4 millimeters since 1959.

Open the Inch unit guide

What is Millimeter?

The millimeter is a unit of length equal to one thousandth of a meter. It is widely used in technical and precision work.

Short history of Millimeter

The millimeter became especially important as manufacturing and engineering required tighter tolerances and repeatable precision.

Open the Millimeter unit guide

Frequently asked questions

How precise are the results?

Conversion results are calculated to 12 significant figures. Very large or very small values are shown in scientific notation.

Is the Inch to Millimeter converter free?

Yes. The conversion tool on BirimCeviri.app is free and requires no sign-up.

Sources

The definitions and conversion relationships on this page are aligned with standard metrology and SI reference material.

  1. BIPM: The International System of Units (SI Brochure)
  2. NIST: SI Units – Length
  3. NIST: Guide for the Use of the International System of Units

Other languages

View the Turkish versionOpen the German version