Time Calculator

A Time Calculator provides the time between two time values. You can use this calculator to add up a timesheet or for time card labor hours.

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What is a Time Calculator?

A Time Calculator, also known as an Hour Calculator or Hours Calculator, quickly and accurately measures how much time has passed based on the start and end times entered in the widget.

Calculating the time is a very basic part of everyday life. At one point or another, we’ve all stared at a clock and tried to work out in our heads how much time it took to finish an activity or task — which is not as easy as it looks.

Most people just approximate it to the nearest hour or fraction of an hour, like half an hour or quarter of an hour, to make things easier. But if you want to get an exact measure of elapsed time down to the last minute, or even up to the last second, an Time Calculator can do it in an instant and with no extra hassles.

A Time Calculator accepts both 12-hour and 24-hour formats and can display the resulting time in hours and minutes, decimal hours, or simply the total number of minutes. The resulting elapsed times are often used in other calculations like:

  • Total charges for labor, work, or billable hours
  • Time clock, time card, and weekly timesheet calculator
  • Activity trackers/monitoring
  • Time management calculators

How to Calculate Elapsed Time and Time Duration

Calculating elapsed time is easier with the 24-hour format, aka military time and the format most used by Europeans. If you’re using the 12-hour or standard time format to record start and end times, you’ll need to convert the recorded times to the 24-hour format first.

To do this, simply add 12 hours to any time recorded during the PM period. Times recorded in the AM stay the same.


1:00 PM = 1:00 + 12:00 = 13:00
5:30 PM = 5:30 + 12:00 = 17:30
8:15 AM = 08:15

To get the time interval, just subtract the start time from the end time, But we need to calculate the difference between the hours and minutes separately.


First convert the recorded times to the 24-hour format.

Start Time: 8:15 AM = 08:15
End Time:  5:30 PM = 17:30

Then subtract the start time from the end time. Do this separately for the hours and minutes.

Elapsed minutes = 30 minutes - 15 minutes = 15 minutes Elapsed hours = 17 hours - 8 hours = 9 hours

Now combine the resulting hours and minutes to get the total elapsed time.

Elapsed time = 9:15 or 9 hours and 15 minutes

If the end time’s minutes is smaller than the start time’s minutes, we’ll get a negative result — which is not a valid time or an accurate measure of the minutes component of the total interval/time duration.

We first need to remove 1 hour from the end time’s hours and then convert that into 60 minutes. When we add the extra 60 minutes to the end time minutes the total time elapsed remains the same and we’ll also end up with a positive number when we subtract the start time’s minutes.


Start Time: 11:47 AM = 11:47
End Time:  1:28 PM = 13:28

28 minutes - 47 minutes gives us -19 minutes which is not a valid time interval.

Subtract 1 hour from the end time’s hours then add 60 minutes to the end time’s minutes.

Converted end time hours = 13 hours - 1 hour = 12 hours Elapsed hours = 12 hours - 11 hours = 1 hour

Converted end time minutes = 28 minutes + 60 minutes = 88 minutes Elapsed minutes = 88 minutes - 47 minutes = 41 minutes

Elapsed time = 1:41 or 1 hour and 41 minutes

The methods for calculating elapsed times described above only work if the start and end times are recorded in the same day.

If the end time falls on the following day but is less than 24 hours from the start time, here’s what you can do:

Start time: 9:35 PM = 21:35
End time:  02:20 AM (of the following day) = 02:20

The end time minutes is smaller than the start time minutes, so we need to remove 1 hour from the end time hours and add it to the end time minutes — otherwise, we’ll end up with a negative number.

Converted end time minutes = 20 minutes + 60 minutes = 80 minutes Elapsed minutes = 80 minutes - 35 minutes = 45 minutes

Since we took out and converted 1 hour from the end time hours, we end up with an end time hour of 1. But since the end time also falls on on the following day, we need to add 24 hours to the hours component to get an accurate number of total hours elapsed and make it work properly with the subsequent calculations.

Converted end time hours = 2 hours - 1 hour + 24 hours = 25 hours Elapsed hours = 25 hours - 21 hours = 4 hours

Elapsed time = 4:45 or 4 hours 45 minutes

To convert the elapsed time into decimal hours, just divide the elapsed minutes by 60. The elapsed hours stay the same and don’t need any conversions.

Using the calculated elapsed time from our last example:

45 minutes ÷ 60 minutes = 0.75 minutes

Use the same number of elapsed hours and just replace the elapsed minutes with the decimal hour equivalent.

4:45 or 4 hours 45 minutes = 4.75 hours

To convert the elapsed time into a total number of minutes, just multiply the elapsed hours by 60, then add the elapsed minutes to the resulting number.

4 x 60 minutes = 240 minutes

240 minutes + 45 minutes = 285 minutes

Why Should You Use a Time Calculator

An Hour and Time Calculator is a very useful tool for anyone wondering “How many hours am I working?”

It’s a useful addition to pages that deal with HR and business operations that deal with calculating shifts and total work hours. Small businesses and professionals can also use it to work out total billable hours and labor charges. It can also be used as an activity tracker which can encompass a variety of topics ranging from time and resource management to health and fitness — among many others.

Adding a Time Calculator widget to your website can help you explain concepts easier and makes it more interactive and dynamic. Because of this, your website visitors are more likely to engage with your page and make an effort to understand what you’re trying to say. If people realize that the information and value proposition that you’re presenting is actually useful, your website and brand gain more credibility — which can help you attract more new visitors to your site and boost your search engine rankings.

Our easy-to-use no code calculator builder can help you design and build any kind of Time Calculator you desire. It doesn’t require any coding knowledge and can use any existing formulas and equations you may already be using in Excel or Google Sheets.

You can also use our default Hour Calculator as is or modify it to suit your specific needs. We also have lots of premade calculator form templates that you can use as a starting point or if you’re just looking for some extra inspiration.

You can add a calculator to any of your pages today completely free of charge if you want to see for yourself how well it can work. We’ll only start charging you once you hit 100 monthly visits on your calculator form. Our flexible pricing model allows you to only pay for the services and features you absolutely need.

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