How Many Millimeters in a Inch?

Quick Answer
1 Inch = 25.4 Millimeters

1 in = 25.4 mm

Formula

mm = in × 25.4

Conversion Table

Inches (in)Millimeters (mm)
1 in25.4 mm
2 in50.8 mm
5 in127 mm
10 in254 mm
20 in508 mm
50 in1,270 mm
100 in2,540 mm
500 in12,700 mm
1,000 in25,400 mm

Worked Examples

Convert 5 in to mm:
5 in × 25.4 = 127 mm
Convert 10 in to mm:
10 in × 25.4 = 254 mm
Convert 50 in to mm:
50 in × 25.4 = 1,270 mm

FAQ

How many Millimeters are in 1 Inch?
There are 25.4 Millimeters in 1 Inch. Formula: mm = in × 25.4.
How to convert Inches to Millimeters?
To convert Inches to Millimeters, multiply the number of Inches by 25.4. For example, 10 in = 254 mm.
How many Millimeters are in 100 Inches?
There are 2,540 Millimeters in 100 Inches. Calculation: 100 × 25.4 = 2,540.