## Unit Converter

## Conversion formula

The conversion factor from days to hours is 24, which means that 1 day is equal to 24 hours:

1 d = 24 hr

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

1 d → 24 hr

21 d → T_{(hr)}

Solve the above proportion to obtain the time *T* in hours:

T_{(hr)} = 21 d × 24 hr

T_{(hr)} = 504 hr

The final result is:

21 d → 504 hr

We conclude that **21 days is equivalent to 504 hours**:

21 days = 504 hours

## Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case **1 hour is equal to 0.001984126984127 × 21 days**.

Another way is saying that *21 days is equal to 1 ÷ 0.001984126984127 hours*.

## Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that **twenty-one days is approximately five hundred four hours**:

21 d ≅ 504 hr

An alternative is also that *one hour is approximately zero point zero zero two times twenty-one days*.

## Conversion table

### days to hours chart

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

days (d) | hours (hr) |
---|---|

22 days | 528 hours |

23 days | 552 hours |

24 days | 576 hours |

25 days | 600 hours |

26 days | 624 hours |

27 days | 648 hours |

28 days | 672 hours |

29 days | 696 hours |

30 days | 720 hours |

31 days | 744 hours |