Time Duration Calculator
Enter a start time and an end time to see exactly how long passed between them, in hours and minutes, decimal hours and total minutes. Subtract an unpaid lunch break, handle shifts that run past midnight, or switch to dates and times to measure spans of several days, like a trip, a rental or a long project.
Updated
Results
- Decimal hoursFor timesheets: 45 min = 0.75
- Total minutes
- Full daysDays of 24 hours, date mode
- PlusHours and minutes after the full days
- EndsThe end time is on the following day
Results are estimates. See the methodology below.
How to use the time duration calculator
- Choose Two times for a span within one shift or day, or Dates and times for a span that covers several days.
- Enter the start time and end time. In date mode, also pick the start and end dates.
- In time mode, enter your unpaid break in minutes, such as 30 for a lunch break. Leave 0 if you had none.
- Read the duration in hours and minutes, the same time in decimal hours (handy for timesheets and payroll) and in total minutes. A Next day note appears when the end time is earlier than the start time. In date mode, spans from 24 hours up are also split into days, hours and minutes.
How the duration is calculated
In time mode the calculator subtracts the start time from the end time. If the end time is earlier than the start time, it assumes the span ends the next day and adds 24 hours. Then it subtracts the break: duration = end − start (+ 24 h if overnight) − break. The break must be shorter than the span. A start and end time that are identical give 0, not 24 hours; use date mode for a full day.
In date mode it measures the gap between the two date-and-time points and, from 24 hours up, shows it as whole 24-hour days plus remaining hours and minutes. The end must come after the start.
Decimal hours are total minutes divided by 60, shown with two decimals: 45 minutes is 0.75 hours.
The calculator works on clock readings only. It has no time zones and ignores daylight saving time. Under the U.S. rule described by NIST, clocks fall back at 2:00 a.m. on the first Sunday of November, so from 4:00 PM on October 23, 2026, to 8:00 AM on November 2, 2026, the calculator shows 232 hours, while 233 hours actually pass where clocks change. Adjust by one hour when a span crosses a clock change.
Examples
A workday with lunch
You clock in at 8:30 AM and out at 4:45 PM with a 30-minute unpaid lunch. The result is 7 h 45 min, or 7.75 hours, or 465 minutes.
A night shift
A shift from 10:15 PM to 6:45 AM with a 30-minute meal break gives 8 h 00 min (8.00 hours, 480 minutes), flagged as ending the next day. Without the break it would be 8 h 30 min.
A weekend away
From Friday, October 9, 2026, at 6:40 PM to Monday, October 12, 2026, at 7:05 AM, date mode returns 60 h 25 min: 2 days plus 12 h 25 min, or 60.42 hours and 3,625 minutes.
Minutes to decimal hours
| Minutes | Decimal hours |
|---|---|
| 5 | 0.08 |
| 10 | 0.17 |
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.50 |
| 40 | 0.67 |
| 45 | 0.75 |
| 50 | 0.83 |
Using the result for timesheets
The U.S. Department of Labor says employers may use any timekeeping method as long as it is complete and accurate, and the records must show hours worked each day and total hours each workweek. A few federal rules affect what you enter here:
- Short breaks count as work. Under 29 CFR 785.18, rest periods of about 5 to 20 minutes must be counted as hours worked, so don't subtract them.
- Meal periods usually don't. Under 29 CFR 785.19, a bona fide meal period, ordinarily 30 minutes or more, is not worktime. That is the break to enter.
- Rounding. Employers may round punch times to the nearest 5 minutes, tenth of an hour or quarter hour if it averages out so employees are paid for all time worked (29 CFR 785.48). This calculator does not round; it shows the exact span.
State laws on breaks and overtime can add to these rules.
Frequently asked questions
How many hours is 9 AM to 5:30 PM?
8 hours 30 minutes, or 8.5 hours. With a 30-minute unpaid lunch it is 8 hours exactly, 480 minutes.
How do I convert minutes to decimal hours?
Divide the minutes by 60. 15 minutes is 0.25 hours, 20 minutes is 0.33 and 45 minutes is 0.75, so 7 hours 45 minutes is 7.75 hours. The calculator shows this automatically next to the hours-and-minutes result.
How do I calculate hours for a shift that goes past midnight?
Just enter the times as they are. If the end time is earlier than the start time, the calculator treats it as the next day: 9:00 PM to 7:30 AM gives 10 h 30 min. For spans longer than 24 hours, switch to dates and times.
Should I subtract my break?
Subtract only unpaid meal breaks. Federal rules count short rest breaks of roughly 5 to 20 minutes as hours worked, while a genuine meal period, usually 30 minutes or more, is not worktime.
Does the calculator handle daylight saving time?
No. It compares clock readings, so a span that crosses the spring or fall clock change is off by one hour. In the U.S. the change happens at 2:00 a.m. on the second Sunday of March and the first Sunday of November.
Can I measure time between two dates?
Yes. Choose Dates and times and enter both dates. You get the total in hours and minutes and, from 24 hours up, full days plus the remaining hours, for example 2 days and 12 h 25 min.
Sources
The calculator measures clock time without time zones or daylight saving time. For pay questions, your employer's records and the federal and state rules that apply to you decide which time counts as work.