## Conversion formula

The conversion factor from inches to millimeters is 25.4, which means that 1 inch is equal to 25.4 millimeters:

1 in = 25.4 mm

To convert 4 inches into millimeters we have to multiply 4 by the conversion factor in order to get the length amount from inches to millimeters. We can also form a simple proportion to calculate the result:

1 in → 25.4 mm

4 in → L(mm)

Solve the above proportion to obtain the length L in millimeters:

L(mm) = 4 in × 25.4 mm

L(mm) = 101.6 mm

The final result is:

4 in → 101.6 mm

We conclude that 4 inches is equivalent to 101.6 millimeters:

4 inches = 101.6 millimeters

## Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 0.0098425196850394 × 4 inches.

Another way is saying that 4 inches is equal to 1 ÷ 0.0098425196850394 millimeters.

## Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that four inches is approximately one hundred one point six millimeters:

4 in ≅ 101.6 mm

An alternative is also that one millimeter is approximately zero point zero one times four inches.

## Conversion table

### inches to millimeters chart

For quick reference purposes, below is the conversion table you can use to convert from inches to millimeters

inches (in) millimeters (mm)
5 inches 127 millimeters
6 inches 152.4 millimeters
7 inches 177.8 millimeters
8 inches 203.2 millimeters
9 inches 228.6 millimeters
10 inches 254 millimeters
11 inches 279.4 millimeters
12 inches 304.8 millimeters
13 inches 330.2 millimeters
14 inches 355.6 millimeters