Time Calculator — Add, Subtract & Time Between
Work out shift lengths and working hours, or add up and subtract durations in hours, minutes and seconds.
Updated
Formula
Duration = End − Start (add 24 h if End < Start)
Total seconds = h × 3600 + m × 60 + s
Durations are converted to seconds, added or subtracted, and converted back.
Examples
9:00 to 17:30
09:00 to 17:30 = 8 hours 30 minutes
Night shift 22:00 to 06:00
22:00 to 06:00 = 8 hours 0 minutes (overnight)
2 h 45 min + 1 h 30 min
Result: 4 h 15 min 0 s
Important information
- Decimal hours are useful for timesheets: 7 h 30 min = 7.5 hours.
Frequently asked questions
How do I calculate hours worked?
Subtract the start time from the end time. For overnight shifts, add 24 hours to the end time first.
How do I convert minutes to decimal hours?
Divide minutes by 60. 45 minutes = 0.75 hours.
Does it handle times past midnight?
Yes — if the end time is earlier than the start time, it is treated as the next day.
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