I am trying to set up an actual flow rate calculation, where I have a volume sampled, a start time, and an end time. I would like to get the flow rate (volume/elapsed time) but I cannot seem to get the formula set up correctly. The times never cross days, so I do not use a date in my time entries (in fact the time is only a few minutes). I have managed to get the correct number of elapsed minutes using the =MINUTES(B28-B26) formula, but if I use that answer cell in my flow rate formula, it does not return the correct answer (I assume it is not returning the minutes calculation as an integer). Can anyone help to set up this equation? Thanks.

✔ Best Answer

Minor modification to get down to Minutes: =((B1-A1)*24)*60

EDIT ADDED:Can you figure out how to get SECONDS? :-)

MIKE

Unless I'm missing something the formula

to get the time difference is simply=End_Time minus Start_Time:

A B C 1) 8:00 11:00 3:00The formula in C1 is simply =B1-A1

Make sure that C1 is formatted as a TIME type cell.

MIKE

Yes, but I need to take that answer and apply it to another formula (volume/time) and that is where the answer is failing in my formula. I need to take the time answer (say 8 minutes) and use that to divide the volume to get a flow rate.

OK, to covert the Time Value to a decimal number,

Format cell C1 as Number and use the formula=(B1-A1)*24

See how that works.

MIKE

Using the followng as the data (9:59 AM start time and 10:08 AM as the stop time), your fomula returned 0.15 with answer cell formated as a decimal number. If I use the (B2-B1) formula and format the answer cell as "Custom" [m] format, I get the right answer (9) but it does not calculate as "9" in the second formula.

Minor modification to get down to Minutes: =((B1-A1)*24)*60

EDIT ADDED:Can you figure out how to get SECONDS? :-)

MIKE

Thanks. That worked, and I was even able to combine the equations and still get it to work.

FYI - Yes to get down to seconds, I assume the equation adjusts to =(((B1-A1)*24)*60)*60

:-)

Just so you know, you can also combine the multipliers: 24 * 60 = 1440

so you could use:

=((B1-A1)*1440)

A wee bit shorter and only one multiplier.

MIKE

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