## Unit Converter

## 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 21 decimeters into millimeters we have to multiply 21 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

21 dm → L_{(mm)}

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

L_{(mm)} = 21 dm × 100 mm

L_{(mm)} = 2100 mm

The final result is:

21 dm → 2100 mm

We conclude that **21 decimeters is equivalent to 2100 millimeters**:

21 decimeters = 2100 millimeters

## Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case **1 millimeter is equal to 0.00047619047619048 × 21 decimeters**.

Another way is saying that *21 decimeters is equal to 1 ÷ 0.00047619047619048 millimeters*.

## Approximate result

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

21 dm ≅ 2100 mm

An alternative is also that *one millimeter is approximately zero times 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

decimeters (dm) | millimeters (mm) |
---|---|

22 decimeters | 2200 millimeters |

23 decimeters | 2300 millimeters |

24 decimeters | 2400 millimeters |

25 decimeters | 2500 millimeters |

26 decimeters | 2600 millimeters |

27 decimeters | 2700 millimeters |

28 decimeters | 2800 millimeters |

29 decimeters | 2900 millimeters |

30 decimeters | 3000 millimeters |

31 decimeters | 3100 millimeters |