Conversion formula

The conversion factor from centimeters to decimeters is 0.1, which means that 1 centimeter is equal to 0.1 decimeters:

1 cm = 0.1 dm

To convert 21 centimeters into decimeters we have to multiply 21 by the conversion factor in order to get the length amount from centimeters to decimeters. We can also form a simple proportion to calculate the result:

1 cm → 0.1 dm

21 cm → L_(dm)

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

L_(dm) = 21 cm × 0.1 dm

L_(dm) = 2.1 dm

The final result is:

21 cm → 2.1 dm

We conclude that 21 centimeters is equivalent to 2.1 decimeters:

21 centimeters = 2.1 decimeters

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 decimeter is equal to 0.47619047619048 × 21 centimeters.

Another way is saying that 21 centimeters is equal to 1 ÷ 0.47619047619048 decimeters.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that twenty-one centimeters is approximately two point one decimeters:

21 cm ≅ 2.1 dm

An alternative is also that one decimeter is approximately zero point four seven six times twenty-one centimeters.

Conversion table

centimeters to decimeters chart

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