Conversion formula

The conversion factor from decimeters to millimeters is 100, which means that 1 decimeter is equal to 100 millimeters:

1 dm = 100 mm

To convert 421 decimeters into millimeters we have to multiply 421 by the conversion factor in order to get the length amount from decimeters to millimeters. We can also form a simple proportion to calculate the result:

1 dm → 100 mm

421 dm → L_(mm)

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

L_(mm) = 421 dm × 100 mm

L_(mm) = 42100 mm

The final result is:

421 dm → 42100 mm

We conclude that 421 decimeters is equivalent to 42100 millimeters:

421 decimeters = 42100 millimeters

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 2.375296912114E-5 × 421 decimeters.

Another way is saying that 421 decimeters is equal to 1 ÷ 2.375296912114E-5 millimeters.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that four hundred twenty-one decimeters is approximately forty-two thousand one hundred millimeters:

421 dm ≅ 42100 mm

An alternative is also that one millimeter is approximately zero times four hundred twenty-one decimeters.

Conversion table

decimeters to millimeters chart

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