loot.tools

Time Duration Calculator

Enter durations one per line - clock form like 1:30:00, unit form like 2h 15m or 1.5h, or a plain number of seconds - and get the running total in HH:MM:SS plus total hours, minutes, and seconds. Start any line with a minus sign to subtract it, so you can mix additions and subtractions in one list. Built for adding up logged hours on a timesheet, summing video clip or track lengths, totalling lap or split times, or working out how much time a set of tasks comes to. Every line is parsed live and anything it can't read is flagged rather than silently dropped. It all runs in your browser.
Time
Durations (one per line)

Use clock form (1:30:00, 45:00), units (2h 15m, 1.5h, 90s), or a plain number of seconds. Start a line with "-" to subtract it.

04:11:30
4h 11m 30s · 5 durations added
Total hours
4.192
Total minutes
251.5
Total seconds
15,090
Parsed lines
1:30:0001:30:00
45m00:45:00
2h 15m02:15:00
-0:20:00-00:20:00
90s00:01:30

What this tool does

It adds up a list of durations and shows the total. Put one duration per line and the total updates as you type, in HH:MM:SS and as plain totals in hours, minutes, and seconds. Each line is parsed on its own and shown back to you, so a typo gets flagged instead of quietly throwing off the result.

Formats you can enter

Clock form like 1:30:00 (hours:minutes:seconds) or 45:00 (minutes:seconds). Unit form like 2h 15m, 1.5h, or 90s, mixing days, hours, minutes, and seconds. Or a bare number, which is read as seconds. Parts can run past 59, so 90:00 means 90 minutes.

Adding and subtracting

Start a line with a minus sign to subtract that duration from the total, so you can mix entries like 8:00:00 and -1:00:00 for a lunch break in the same list. The total can go negative, which is shown with a leading minus. Useful for timesheets, media editing, lap and split times, or any time you need to total a stack of durations.