## Millimeters-Inches Converter

Enter the length in either of the next two fields and get it converted instantly from mm to inches or the opposite, from inches to mm. Inches are printed both in decimal and fraction form.

 Millimeters [mm]: Inches [in]: Fraction [in]:

### Conversion Formulas

1 inch = 25.4 mm

1 mm ≈ 0.03937 inches

## Definitions

### Unit of millimeter

The millimeter or millimetre [mm] is a unit of length from the SI system of units. It is defined as one thousandth (1/1000) of the meter. The meter [m], is the base unit of length in SI system, and is currently established as the distance traveled by light in vacuum in $$\frac{1}{299\,792\,458}$$ seconds.

Common multiple and fraction units of the metre are defined through the decimal SI prefixes, as presented in the following table:

### Unit of inch

Inch [in] is a unit of length in the Imperial and US customary system of units. It was historically conceived as the length of 3 barley-corns. Today, it is defined through the meter SI unit as: 1 in = 0.0254 m (= 2.54 cm = 25.4 mm).

Multiple units of the inch are defined as shown in the table:

### How to convert inches to mm

• Multiply distance in [in] with 25.4
• The result is the distance in mm

For example, to convert 1/2 inches to mm, do: $$0.5\times 25.4 = 12.7$$ mm

### How to convert mm to inches

• Divide distance in [mm] by 25.4
• The result is the distance in inches

For example, to convert 150 mm to inches, do: $$150/25.4 \approx 5.91$$ inches

### Conversion table from mm to inches

In the following table some typical distances in millimeters are converted to inches:

[mm][in]
0.5
1
2
3
5
10
12
20
30
40
50
100
200
300
400
500
600
700
800
900
1000

### Conversion table from inches to mm

In the following table some typical distances in inches are converted to millimeters:

[in][mm]
0.125
0.25
0.375
0.5
1
2
3
5
10
12
20
30
50