Category: Date & time
Time Duration Calculator
Add, subtract and convert durations
Enter two durations in weeks, days, hours, minutes and seconds, add or subtract them, and read the result as a human-readable breakdown and as a total in every unit.
Duration A
Duration B
Result
0 weeks, 4 days, 0 hours, 45 minutes, 0 seconds
The calculation happens in the page. Nothing is sent anywhere.
Everything on this page is processed in your browser. Nothing is uploaded.
What this tool does
Adding '3 days 6 hours' to '18 hours 45 minutes' by hand means carrying between five different units, which is easy to get wrong the same way long division is. This tool does that carrying for you and shows both a plain-language breakdown, such as '4 days, 0 hours, 45 minutes', and the same total converted into a single number of weeks, days, hours, minutes or seconds, so whichever unit the next step needs is already there. Subtracting a longer duration from a shorter one gives a negative result rather than an error, since a schedule running behind is a real answer, not an invalid one.
How to use it
- Enter Duration A in weeks, days, hours, minutes and seconds.
- Enter Duration B the same way, and choose add or subtract.
- Read the combined duration as a breakdown and as a total in each unit.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- Does this use time zones or calendar dates?
- No. It only adds lengths of time, such as '2 days' or '5 hours', with a week fixed at 7 days and a day at 24 hours. There is no date, time zone or daylight-saving adjustment involved.
- What happens if I subtract a longer duration from a shorter one?
- The result is negative, shown with a minus sign in the breakdown, rather than an error.
- Is anything sent to a server?
- No. The arithmetic runs in the page as you type.