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 18 decimeters into millimeters we have to multiply 18 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

18 dm → L_(mm)

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

L_(mm) = 18 dm × 100 mm

L_(mm) = 1800 mm

The final result is:

18 dm → 1800 mm

We conclude that 18 decimeters is equivalent to 1800 millimeters:

18 decimeters = 1800 millimeters

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 millimeter is equal to 0.00055555555555556 × 18 decimeters.

Another way is saying that 18 decimeters is equal to 1 ÷ 0.00055555555555556 millimeters.

Approximate result

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

18 dm ≅ 1800 mm

An alternative is also that one millimeter is approximately zero point zero zero one times eighteen 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