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 421.5 millimeters into inches we have to multiply 421.5 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

421.5 mm → L_(in)

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

L_(in) = 421.5 mm × 0.039370078740157 in

L_(in) = 16.594488188976 in

The final result is:

421.5 mm → 16.594488188976 in

We conclude that 421.5 millimeters is equivalent to 16.594488188976 inches:

421.5 millimeters = 16.594488188976 inches

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 inch is equal to 0.060260972716489 × 421.5 millimeters.

Another way is saying that 421.5 millimeters is equal to 1 ÷ 0.060260972716489 inches.

Approximate result

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

421.5 mm ≅ 16.594 in

An alternative is also that one inch is approximately zero point zero six times four hundred twenty-one point five 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