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 120 decimeters into millimeters we have to multiply 120 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

120 dm → L_(mm)

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

L_(mm) = 120 dm × 100 mm

L_(mm) = 12000 mm

The final result is:

120 dm → 12000 mm

We conclude that 120 decimeters is equivalent to 12000 millimeters:

120 decimeters = 12000 millimeters

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 8.3333333333333E-5 × 120 decimeters.

Another way is saying that 120 decimeters is equal to 1 ÷ 8.3333333333333E-5 millimeters.

Approximate result

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

120 dm ≅ 12000 mm

An alternative is also that one millimeter is approximately zero times one hundred twenty 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