Sum of time

This sum of time calculator allows you to add or subtract periods of time expressed in days, hours, minutes and seconds in a quick and easy way.

Unlike other dimensions like distance or weight, time is measured in sexagesimal, not decimal units: 1 hour does not have 100 minutes, but 60. This makes quite complex adding or substractiong this type of units.

This sum of time calculator allows you to add and subtract up to 10 different periods.

You can use it to find out how long it takes you to carry out different activities; for instance, you can:

  • Calculate how long you have exercised this week.
  • Compute the extra hours you have worked.
  • Calculate how long you have spent on a project.
  • Add the time you have devoted to your children this week.
  • Calculate how much time you have spent studying this week.
  • Discount the vacation or sick time from your working time.


  • Enter each period of time in a row, broken down into days, hours, minutes and seconds.
  • Select the operator that corresponds to each period: A plus sign means that its value is added; a minus sign that is subtracted; a 0 means that it is not taken into account in the computation.
  • The result is automatically displayed below.

Related calculators

Do you need to calculate the arithmetic mean of several periods of time? You can use the average time calculator.