Time calculator
Add or subtract clock durations without carrying errors. Sum billable hours (2h 45m + 3h 30m), subtract break time from shift length, or total segments in hh:mm:ss. Handles overflow past 60 minutes and 24 hours when summing durations (not clock times on a day boundary).
Hours
Minutes
Add hours
Add minutes
Result
17:15
How to add or subtract time
1. Enter first duration in hours, minutes, seconds (or hh:mm:ss).
2. Enter second duration and choose add or subtract.
3. Read total or difference in normalized form.
4. For clock times crossing midnight, use a date-aware tool if needed.
Time calculation examples
Freelance hours
Monday 2h 15m + Tuesday 3h 50m + Wednesday 1h 05m = 7h 20m billable.
Video edit runtime
Three clips: 04:32 + 12:08 + 00:55 = 17:35 total footage before transitions.
Subtract break
8h 00m shift − 0h 45m lunch = 7h 15m paid time (policy-dependent).
When to use the time calculator
• When you total weekly timesheet entries without spreadsheet formulas.
• When you sum podcast or media segment lengths.
• When you plan cooking stages with multiple timed steps.
When to choose something else
• When you need timezone conversion — use timezone tools.
• When you compute business days between dates — use days-between-dates with business rules.
• When you schedule recurring calendar events — use calendar apps.
Duration vs time-of-day
Adding 2h 30m to 11:00 PM yields 1:30 AM next day — a calendar problem. Adding durations 2h 30m + 3h 15m = 5h 45m is pure duration math. Pick the right tool for the question.
Billing in 6-minute increments
Law firms often bill 0.1 hr (6 min) ticks. Convert minutes to decimal hours: 42 min = 0.7 hr. Sum decimals, then convert back for display if needed.
Frequently asked questions
Does it wrap at 24 hours?
Duration sums can exceed 24h (e.g. 30h total project time). Clock time mode may wrap differently.
Can I enter decimal hours?
Some tools accept 1.5 h = 1h 30m. Check input mode.
Subtract larger from smaller?
May show negative duration or error — useful for checking overtime balance.
Seconds required?
Optional — leave 0 if you only track hours and minutes.
Difference from working hours calculator?
Working hours often handles start/end clock times and breaks; this tool sums arbitrary durations.
Is data uploaded?
No. Calculations run locally.