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Convert Excel time to decimal seconds

Excel formula: Convert Excel time to decimal seconds
Generic formula 

To convert a valid Excel time into decimal seconds, you can multiply by 86400. In the example shown, the formula in C6 is:


which returns a value of 60, since there are 60 seconds in 1 minute.

How this formula works

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, convert to decimal minutes by multiplying the value by 1440 (24 * 60) , and convert to seconds by multiplying by 86400 (24 * 60 * 60).

With the time value 6:00 cell A1, you can visualize the conversion like this:


The Excel time 6:00 converts to 21,600 seconds.

Format result as number

When you multiply a time value by 86400, 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.

Dave Bruns

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