Time Duration Calculator
This time duration calculator finds the hours and minutes between a start time and an end time, including spans that cross midnight. It can subtract a break, and it shows the result in decimal hours for timesheets and pay.
Result
8 hours 30 minutes
| Decimal hours | 8.5 |
|---|---|
| Total minutes | 510 |
Results update as you type.
How to Calculate Time Duration
- Write both times in 24-hour format: 5:30 p.m. is 17:30.
- If the end time is earlier than the start time, the span crosses midnight, so add 24 hours to the end time.
- Subtract: hours from hours and minutes from minutes, borrowing 60 minutes if needed.
- Subtract any unpaid break.
Decimal hours
Decimal hours = hours + minutes ÷ 60
| Minutes | Decimal |
|---|---|
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.5 |
| 40 | 0.67 |
| 45 | 0.75 |
Worked Example
A shift from 9:00 a.m. to 5:30 p.m. with a 30-minute unpaid lunch:
- In 24-hour time: 09:00 to 17:30
- 17:30 − 09:00 = 8 hours 30 minutes
- Minus the break: 8 hours, or 8.0 decimal hours
An overnight shift from 10:00 p.m. to 6:15 a.m.: (6:15 + 24:00) − 22:00 = 8 hours 15 minutes, or 8.25 hours.
Tips
Rounding on timesheets
Some employers round clock-in times to the nearest 5, 6 or 15 minutes. Use the exact times here, then apply your employer’s rule.
A full week of shifts
To total several days and work out pay with overtime, use the time card calculator.
Sleep
To plan a bedtime around sleep cycles instead, try the sleep calculator.
Frequently Asked Questions
How do I calculate the hours between two times?
Subtract the start time from the end time. From 9:00 a.m. to 5:30 p.m. is 8 hours 30 minutes. If the minutes of the end time are smaller, borrow an hour as 60 minutes, so 5:15 p.m. − 9:40 a.m. is 16:75 − 9:40 = 7 hours 35 minutes.
How do I calculate time that goes past midnight?
Add 24 hours to the end time before subtracting. A shift from 10:00 p.m. to 6:15 a.m. is (6:15 + 24:00) − 22:00 = 8 hours 15 minutes. The calculator does this automatically when the end time is earlier than the start time.
How do I convert minutes to decimal hours?
Divide the minutes by 60. 30 minutes is 0.5 hours, 15 minutes is 0.25 and 45 minutes is 0.75. So 8 hours 30 minutes is 8.5 hours, which is the figure to multiply by an hourly rate.
What is 8:30 in decimal hours?
8.5. The 30 minutes is half an hour. Be careful not to read 8 hours 30 minutes as 8.30 hours, which would be about 8 hours 18 minutes.
Should breaks be subtracted?
For paid time, subtract unpaid breaks such as a lunch break. Under U.S. federal rules, short rest breaks of about 5 to 20 minutes are generally counted as paid work time, while bona fide meal periods, usually 30 minutes or more, are generally not.
Can I add up a whole week of hours?
Yes, the time card calculator takes start and end times and breaks for each day, adds up the week and works out pay, including overtime.
Related Calculators
- Time Card CalculatorWeekly hours, overtime and gross pay from daily start and end times.
- Date Difference CalculatorDays, weeks, months and weekdays between two dates.
- Age CalculatorExact age in years, months and days, and days to the next birthday.
- Sleep CalculatorBedtimes and wake-up times that line up with full sleep cycles.
- Percentage CalculatorPercent of a number, what percent X is of Y, and percent change.
Sources & Assumptions
- U.S. Department of Labor, Wage and Hour Division — Breaks and meal periods (short breaks are usually paid work time; bona fide meal periods of 30 minutes or more generally are not)
- Times use the 24-hour clock internally. An end time earlier than the start time is treated as the next day. Equal start and end times give 0, not 24 hours.
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