Calculate days from hours, or hours from days, using a 24-hour calendar day, an 8-hour work day, or a custom day length.
Hours to Days Formula
This calculator works in two modes, and both use the number of hours in a single day to move between the two units. You choose how long one day is: a 24-hour calendar day, an 8-hour work day, or a custom value.
To convert hours into days, divide the hours by the length of one day:
Days = Hours / H
To convert days into hours, multiply the days by the length of one day:
Hours = Days * H
- Days = number of days
- Hours = number of hours
- H = hours in one day (24 for a calendar day, 8 for a work day, or a custom value you enter)
The mode selector decides which formula runs. In hours to days mode you enter hours and the calculator divides by H. In days to hours mode you enter days and the calculator multiplies by H. The day length selector sets H. A calendar day uses 24, which is the standard conversion most people want. A work day uses 8, which is useful for turning logged hours into work days. The custom option lets you set any day length, such as 7.5 hours, when your day is shorter or longer than a normal shift. The result is also broken down into whole days, hours, and minutes, and into total minutes and seconds.
Hours to Days Conversion Reference
The table below lists common hour amounts converted using a 24-hour calendar day. Divide by 24 to get the decimal days shown here.
| Hours | Days (24-hour day) | Days, hours |
|---|---|---|
| 12 | 0.5 | 0 days, 12 hours |
| 24 | 1 | 1 day, 0 hours |
| 48 | 2 | 2 days, 0 hours |
| 72 | 3 | 3 days, 0 hours |
| 100 | 4.17 | 4 days, 4 hours |
| 168 | 7 | 7 days, 0 hours |
The day length you pick changes the result. The next table shows how the same 40 hours convert under each day definition.
| Day definition | Hours per day (H) | 40 hours equals |
|---|---|---|
| Calendar day | 24 | 1.67 days |
| Work day | 8 | 5 days |
| Custom (7.5) | 7.5 | 5.33 days |
Example Problems
Example 1: Hours to days. You have 100 hours and want to know how many calendar days that is. Using a 24-hour day, divide 100 by 24 to get 4.17 days. Broken down, that is 4 days and 4 hours, because 4 days account for 96 hours and the remaining 4 hours are left over.
Example 2: Days to hours on a work day. You logged 5 work days and want the total hours at 8 hours per day. Switch to days to hours mode, set the day length to the 8-hour work day, and enter 5. Multiply 5 by 8 to get 40 hours.
Frequently Asked Questions
How many days is a given number of hours? Divide the hours by the number of hours in one day. For standard calendar conversions that number is 24, so 48 hours is 2 days and 36 hours is 1.5 days. If you are counting work days instead, divide by the length of your work day, such as 8 hours.
What is the difference between a calendar day and a work day here? A calendar day is 24 hours, the full length of a day on the clock. A work day is the number of hours in a shift, set to 8 by default. Use the calendar day to convert clock time, and use the work day to turn logged or scheduled hours into the number of work days they fill.
Can I convert a decimal number of hours or days? Yes. You can enter values like 2.5 hours or 3.25 days, and the calculator returns a decimal result along with a breakdown into days, hours, and minutes. You can also set how many decimal places the result uses in the advanced options.
