Explanation
In the Excel date system, one day is equal to 1, so you can think of time as fractional values of 1, as shown in the table below:
| Hours | Fraction | Minutes | Seconds | Value | Time |
|---|---|---|---|---|---|
| 1 | 1/24 | 60 | 3600 | 0.04167 | 1:00 |
| 3 | 3/24 | 180 | 10800 | 0.125 | 3:00 |
| 6 | 6/24 | 360 | 21600 | 0.25 | 6:00 |
| 12 | 12/24 | 720 | 43200 | 0.5 | 12:00 |
| 18 | 18/24 | 1080 | 64800 | 0.75 | 18:00 |
| 24 | 24/24 | 1440 | 86400 | 1.0 | 21:00 |
Since there are 24 hours in a day, 60 minutes in each hour, and 60 seconds in each minute, you need to divide by 24 * 60 * 60 = 86400 in order to convert decimal seconds to a value that Excel will recognize as time. After dividing by 86400, you can apply a time format of your choice, or use the result in a math operation with other dates or times.
In the example, since B11 contains 43200 (representing 43200 seconds, or a half day) the result is 43200/86400 = 0.5. Once a time format like h:mm or [h]:mm is applied, Excel will display 12:00.
Displaying a time duration
To display hours that represent a duration longer than 24 hours, minutes in durations longer than 60 minutes, or seconds in durations over 60 seconds, you’ll need to adjust the number format by adding square brackets.
[h] // for hours greater than 24
[m] // for minutes greater than 60
[s] // for seconds greater than 60
The brackets tell to Excel the time is a duration, and not a time of day.
Note: to use square brackets, you’ll need to create and apply a custom number format . Select cells, then go to Format Cells (Control + 1) > Number > Custom.
Explanation
In the Excel time system, one 24-hour day is equal to 1. This means times and hours are fractional values of 1, as shown in the table below:
| Hours | Time | Fraction | Value |
|---|---|---|---|
| 1 | 1:00 AM | 1/24 | 0.04167 |
| 3 | 3:00 AM | 3/24 | 0.125 |
| 6 | 6:00 AM | 6/24 | 0.25 |
| 4 | 4:00 AM | 4/24 | 0.167 |
| 8 | 8:00 AM | 8/24 | 0.333 |
| 12 | 12:00 PM | 12/24 | 0.5 |
| 18 | 6:00 PM | 18/24 | 0.75 |
| 21 | 9:00 PM | 21/24 | 0.875 |
Because each hour can be represented as 1/24, you can convert an Excel time into decimal hours by multiplying the value by 24. For example, with the time value 6:00 cell A1, you can visualize the conversion like this:
=A1*24
=(6/24)*24
=0.25*24
=6
Format result as number
When you multiply a time value by 24, Excel may automatically format the result using a time format like h:mm, which will display the value incorrectly. To display the result as a regular number, apply the General or Number format .