OTHER · TIME DURATION
Time Duration Calculator
Convert between HH:MM:SS and decimal hours for timesheets and payroll. Handles minute and second overflow automatically (75 minutes → 1h 15m).
1.5
decimal hours
1h 30m 0s = 1.5 h (90 min)
About This Calculator
Convert a duration between hours-minutes-seconds and decimal hours — the conversion you need for timesheets, payroll, and billing. Minute and second overflow is handled automatically.
How It Works
Pick a direction. Going HH:MM:SS → decimal, the tool adds up the total seconds and divides by 3600. Going decimal → HH:MM:SS, it multiplies by 3600 and splits the total seconds back into whole hours, minutes, and seconds.
The Formula
total seconds = hours×3600 + minutes×60 + seconds; decimal hours = total seconds ÷ 3600. Inputs outside the usual 0–59 range carry over (e.g. 90 minutes becomes 1h 30m).
Frequently Asked Questions
- How do I convert 1 hour 30 minutes to decimal hours?
- 1h 30m = 1 + 30/60 = 1.5 decimal hours. Thirty minutes is half an hour, so the decimal part is 0.5.
- What is 0.25 hours in minutes?
- 0.25 × 60 = 15 minutes. Quarter-hour increments are 0.25, 0.5, and 0.75 decimal hours.
- Can I enter more than 59 minutes or seconds?
- Yes. The calculator carries the overflow automatically — entering 75 minutes returns 1h 15m, and 90 seconds becomes 1m 30s.