Time Duration Calculator
For timesheets, shifts, flights, and sleep. Handles times past midnight.
How it works
The calculator converts both times to minutes since midnight and subtracts. If the end time is earlier than the start, it assumes the period runs past midnight and adds 24 hours, so 22:00 to 06:00 gives 8 hours and 0 minutes rather than a negative number. A shift from 08:45 to 17:15 comes to 8 hours 30 minutes.
Minutes to decimal hours
Timesheets and invoices usually want hours as a decimal. Divide the minutes by 60 and add them to the whole hours: 7 hours 45 minutes is 7.75 hours.
| Minutes | Decimal hours |
|---|---|
| 0 | .00 |
| 5 | .08 |
| 6 | .10 |
| 10 | .17 |
| 12 | .20 |
| 15 | .25 |
| 18 | .30 |
| 20 | .33 |
| 25 | .42 |
| 30 | .50 |
| 35 | .58 |
| 40 | .67 |
| 45 | .75 |
| 50 | .83 |
| 55 | .92 |
The 6, 12, and 18 minute rows are there because many payroll systems round to tenths of an hour, which are six-minute blocks.
Breaks and rounding
The result is the total time between the two clock times. Subtract any unpaid breaks yourself. Some employers round each clock-in and clock-out to the nearest 5, 6, or 15 minutes, so a paycheck can differ slightly from the exact duration.
Limits
The calculator works with times on a 24-hour clock and assumes the period is under 24 hours. It doesn’t adjust for a daylight saving change during the period, which adds or removes an hour on two nights a year in many countries. For spans of days, use the days until calculator.