This calculator is designed to help you perform time calculations such as adding and subtracting time and converting time formats.
- Enter your time variables by clicking on the calculator buttons on the screen. You can enter a string of digits to represent seconds, or
separate digits using the : button to represent days, hours, minutes and seconds (D:H:M:S). For example, enter 500 for 500 seconds, or
1:12:30:50 for 1 day, 12 hours, 30 minutes and 50 seconds.
- The + or − buttons allow you to add or subract two or more time values.
- The calculator works in 24-hour time so AM/PM is not used. For example, to calculate hours worked if you started at 7:30AM and finished at 3:30PM,
first convert PM times to 24-hour time by adding 12 hours. Therefore, you would calculate 3:30:00 + 12:00:00 - 7:30:00 resulting in 8 hours. See the notes
below if you need more information on how to enter these time values.
- If you enter a number of seconds and click the = button or press the Enter key on your keyboard, the calculator will
convert those seconds into D:H:M:S time format. For example, enter 86400 to see the result converted to 1 day.
- You can mix time formats in your calculations, such as using seconds for one value and D:H:M:S format for another.
- As an alternative, you can enter some values with your keyboard. See below for details.
- Click the = button to see your result.
You may also like to try these calculators:
Click here to try our other Time/Date Calculators.
Here is a list of some of the keyboard shortcuts that can be used to enter values instead of clicking the buttons on the calculator above.
||Clear (C) and All Clear (AC)
|0 1 2 3 4
5 6 7 8 9
|Insert corresponding digit
||Time value separator
||Delete last character
|Number + Enter
||Convert seconds into D:H:M:S time format
|Enter or Return
Please note, some keyboard shortcuts don't work in some browsers.
For reference, an hour has 3,600 seconds, a day has 86,400 seconds, a week has 604,800 seconds and a non-leap year has 31,536,000 seconds.
To calculate 3:30:00 + 12:00:00 - 7:30:00, the calculator button sequence would be: