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 420.9 millimeters into inches we have to multiply 420.9 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

420.9 mm → L_(in)

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

L_(in) = 420.9 mm × 0.039370078740157 in

L_(in) = 16.570866141732 in

The final result is:

420.9 mm → 16.570866141732 in

We conclude that 420.9 millimeters is equivalent to 16.570866141732 inches:

420.9 millimeters = 16.570866141732 inches

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 inch is equal to 0.060346875742457 × 420.9 millimeters.

Another way is saying that 420.9 millimeters is equal to 1 ÷ 0.060346875742457 inches.

Approximate result

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

420.9 mm ≅ 16.571 in

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