Conversion formula

The conversion factor from millimeters to inches is 0.039370078740157, which means that 1 millimeter is equal to 0.039370078740157 inches:

1 mm = 0.039370078740157 in

To convert 25.4 millimeters into inches we have to multiply 25.4 by the conversion factor in order to get the length amount from millimeters to inches. We can also form a simple proportion to calculate the result:

1 mm → 0.039370078740157 in

25.4 mm → L_(in)

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

L_(in) = 25.4 mm × 0.039370078740157 in

L_(in) = 1 in

The final result is:

25.4 mm → 1 in

We conclude that 25.4 millimeters is equivalent to 1 inches:

25.4 millimeters = 1 inches

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 inch is equal to 1 × 25.4 millimeters.

Another way is saying that 25.4 millimeters is equal to 1 ÷ 1 inches.

Approximate result

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

25.4 mm ≅ 1 in

An alternative is also that one inch is approximately one times twenty-five point four millimeters.

Conversion table

millimeters to inches chart

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