How To Calculate The Duration Between 2 Times

There are 2 basic methods to calculate the difference between 2 times. For instance, what is the duration between 9:00am and 5:45pm, the answer is 8.75 hours OR 8 hours and 45 minutes. You may want to calculate times for payroll and timecard purposes, or maybe you’re just interested in how long a task takes to complete. The first method is to use a time calculator to automatically determine the time duration, this is the easiest way. If you are a diehard and want to do the math manually, we give you the instructions below. This tool is offered free use by OnTheClock, Employee Time Clock

Method 1 - Use This Time Duration Calculator

To use the calculator, simply enter a start time, for instance 8:05am, then enter an end time such as 12:45pm. The calculator will automatically generate the time duration in decimal hours (e.g. 4.67 hours) and in hours and minutes (e.g. 4 hours and 40 minutes)

Time Duration Calculator

Start Time
(eg 8:00 am)
End Time
(eg 5:00 pm)
0 hours
or
0 hours

We provide the output in 2 formats, 4.67 hours and 4h and 40m. The decimal version(4.67) makes is easy to do the math to calculate payroll. For instance 40.25 hours X $15.00 per hour = $603.75. The hours/minutes format is generally used when communicating a time value verbally or in writing. This is by far the easiest way to calculate the span between two time, as the manual calculations take way more time and are very error prone. OnTheClock recommends using a calculator over the manual method, however for thoroughness we have included the calculations below.

Method 2 - Do The Time Calculation Math Manually

You can also do the math to manually calculate the difference between a start and end time. Here we will examine how you would calculate the duration between 9:07am and 3:42pm. Math To Calculate Difference Between 2 Times

  1. Convert both times to 24 hour format, adding 12 to all pm hours
    • 9:07am becomes 9:07 hours (start time)
    • 3:42pm becomes 15:42 hours (end time)
  2. If the start minutes are greater than the end minutes…
    • Subtract 1 hour from the end time hours – not applicable to this example
    • Add 60 minutes to the end minutes – not applicable to this example
  3. Subtract end time minutes from start time minutes…
    • 42 – 07 = 35 minutes
  4. Subtract the hours…
    • 9 – 3 = 6 hours
  5. Put(not add) the hours and minutes together – 6:45 (6 hours and 45 minutes)
Here is an example where the start minutes are greater than the end minutes – 8:55am to 3:42pm
  1. Convert both times to 24 hour format, adding 12 to any pm hours
    • 8:55am becomes 8:55 hours (start time)
    • 3:42pm becomes 15:42 hours (end time) <- 12 added
  2. If the start minutes are greater than the end minutes…
    • Subtract 1 hour from the end time hours – 15:42 becomes 14:42
    • Add 60 minutes to the end minutes – 14:42 becomes 14:102
  3. Subtract end time minutes from start time minutes…
    • 102 – 55 = 47 minutes
  4. Subtract the hours…
    • 14 - 8 = 6 hours
  5. Put(not add) the hours and minutes together – 6:45 (6 hours and 45 minutes)

Here we show you two ways to figure the duration (or difference) between a start time and an end time. While doing the calculations manually may be fun for some people, most will agree that the benefits of using a calculator far outweigh the pain and errors of manual time calculations. Feel free to link to this calculator from your website. You many also want to check out these additional free time tools…

time difference duration calculator

Add The Time Duration Calculator To Your Site

Now you can allow your team or your customers to use this tool. With a simple copy and paste, the calculator can be added to your site.

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