add / subtract
chain durations together: "2h 30m", "1:45", "90m", "1.5h"
- =
[ output ]
› 3 hours, 55 minutes
- total seconds
- 14,100
- total minutes
- 235
- total hours
- 3.917
- hh:mm:ss
- 3:55:00
── about this calculator ──
The add / subtract calculator is a stack-based mini calculator for time. Instead of pulling out a spreadsheet to total a column of stopwatch splits or shift lengths, you can type each duration in its natural form — 2h 30m, 1:45, 90m, even 1.5h — and toggle the operator on each row. The result updates as you type.
Common uses: tallying lap times, summing meeting blocks for a day, reconciling a contractor invoice against your own records, or planning a multi-leg journey by adding driving segments and subtracting expected breaks. Because everything runs locally, you can keep adding rows without ever hitting a "calculate" button.
[ worked example ]
input › 8h − 1:00 (lunch) − 0:15 (call) + 0:45 (overtime)
output › 7 hours, 30 minutes (27,000 seconds)
── frequently asked ──
- › What duration formats can I type?
- Combinations of hours, minutes, and seconds: '2h 30m', '1:45' (h:m), '1:45:30' (h:m:s), '90m', '1.5h', '2d', or a plain number which is read as minutes.
- › Can I chain more than two durations?
- Yes. Click 'add row' to add as many lines as you need. Each row has its own + or − operator so you can build expressions like 8h − 0:45 + 1:15 − 0:20.
- › What if my total goes negative?
- That's fine — the result is shown with a leading minus sign. Negative totals are useful for things like 'how much under my budgeted hours did I work this week?'.
- › Is there a limit on the size of durations?
- Practically no. The calculator works in seconds and is accurate well past a human lifetime in either direction.