Convert mm to inches

Enter the value to convert from millimeter to inch.

mm
in
Result: 25 millimeters (mm) = 0.984251968504 inches (in)
OR
63/64 inch

How to Convert Millimeter to Inch

Converting millimeter to inch is straightforward using our conversion calculator.

Conversion Formula

in = mm ÷ 25.4

Reverse conversion: Convert inches to mm

Comparison: Millimeter vs Inch

When to Use Each Unit

Millimeter: Standard in engineering, manufacturing, medicine, and any field requiring precise measurements. Used for tolerances and small components.

Inch: Primary length unit in the United States for construction, manufacturing, and everyday measurements.

Common Conversion Values

  • 1 mm = 0.1 cm
  • 1 mm ≈ 0.0394 in
  • 25.4 mm = 1 in
  • 1000 mm = 1 m

About Millimeter

Definition: The millimeter (symbol: mm) is a unit of length equal to one thousandth of a meter. Used for precise measurements and small dimensions.

History: Developed alongside the metric system for measurements requiring higher precision than centimeters could provide.

Current Use: Standard in engineering, manufacturing, medicine, and any field requiring precise measurements. Used for tolerances and small components.

Examples: Paper thickness: 0.1mm, coin thickness: 1-3mm, drill bits: 1-20mm, rainfall: measured in mm

About Inch

Definition: The inch (symbol: in) is an imperial unit of length equal to 1/12 of a foot, approximately 2.54 centimeters.

History: Originally based on the width of a human thumb. Standardized in 1959 as exactly 25.4 millimeters internationally.

Current Use: Primary length unit in the United States for construction, manufacturing, and everyday measurements.

Examples: Screen sizes: 15-32 inches, screw sizes: 1/4-1 inch, lumber: 2×4 inches, pipe diameters: 1/2-12 inches

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