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Unit Converter

Inch to Millimeter

1 in = 25.4 mm
Swap: Millimeter to Inch⇄

1 Inch (in) is equal to 25.4 Millimeter (mm).To convert from inch into millimeter, calculate using the recognized factor equation: 1 × 25.4 = 25.4 mm. Enter any value into the calculator below for automatic multi-unit calculations across the entire system.

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How to Convert Inch to Millimeter

Exact Formula

To convert from Inch (in) to Millimeter (mm), apply the standard mathematical equation:

Value in mm = Value in in × (25.4)
Example: 1 × 25.4 = 25.4 mm

1 Inch (in) is equal to exactly 25.4 Millimeter (mm).

Reverse conversion: 1 mm = 0.03937 in.

Inch to Millimeter Conversion Table

Quick lookup for standard increments from 1 to 100 in

Reference Table
Inch (in)Millimeter (mm)Quick Copy
1 in25.4 mm
2 in50.8 mm
3 in76.2 mm
5 in127 mm
10 in254 mm
15 in381 mm
20 in508 mm
25 in635 mm
50 in1,270 mm
75 in1,905 mm
100 in2,540 mm

Related Length Conversions

Quick jumps from Inch to other popular length units

Cluster Links
Inch to Meter1 in = 0.0254 mInch to Kilometer1 in = 2.5400e-5 kmInch to Centimeter1 in = 2.54 cmInch to Mile1 in = 1.5783e-5 miInch to Yard1 in = 0.0278 ydInch to Foot1 in = 0.0833 ft

Frequently Asked Questions

Common queries regarding Inch to Millimeter calculation formulas

How many millimeter are in 1 inch?

There are exactly 25.4 millimeter (mm) in 1 inch (in).

What is the formula to convert from Inch to Millimeter?

To convert Inch to Millimeter: Value in mm = Value in in × (25.4). 1 Inch (in) is equal to exactly 25.4 Millimeter (mm).

How do you convert Millimeter back into Inch?

To convert in reverse from Millimeter to Inch, 1 mm equals approximately 0.03937 in.