About this tool
This calculator finds the exact elapsed time between a start and end clock time — down to the second, plus a decimal-hours total that's handy for timesheets. Everything runs locally in your browser.
How to use the Time Duration Calculator
- Enter the start time and end time.
- Check "End time is the next day" if the shift crosses midnight.
- Read the duration — hours, minutes, seconds, and totals.
Common use cases
- Calculating hours worked for a timesheet, including a shift that crosses midnight
- Finding a race or workout split time between a start and finish
- Working out how long a meeting, flight, or appointment actually lasted
Worked example
A shift from 9:00 PM to 5:30 AM the next morning: enter 9:00 PM as the start time, 5:30 AM as the end time, and check "End time is the next day." The result is 8 hours and 30 minutes — without that checkbox checked, the calculator shows a duration of 0, since 5:30 AM comes before 9:00 PM on the same clock face. The decimal-hours figure (8.5) is the one most timesheet and payroll systems expect, rather than "8 hours 30 minutes" written out.
Things to watch out for
This tool works with a single day's clock times, not calendar dates — if you need the duration between two specific dates (like "March 3 to July 19"), use the Relationship Day Counter or Age Calculator instead, both of which handle full dates. Seconds are optional — if your browser's time picker doesn't show a seconds field, the calculation still works correctly using whole minutes.
Time math examples
| Calculation | Result |
|---|---|
| 9:00 AM to 5:30 PM | 8 hours 30 minutes |
| 10:15 PM to 6:45 AM | 8 hours 30 minutes |
| 2 h 20 min + 1 h 50 min | 4 hours 10 minutes |
| 3.5 hours | 3 hours 30 minutes |
| 90 minutes | 1 hour 30 minutes |
When a shift crosses midnight, add 24 hours to the end time before subtracting.
Clock time versus decimal time
Payroll and invoices usually want decimal hours, while clocks use hours and minutes. To convert, divide the minutes by 60: 7 hours 45 minutes is 7.75 hours, and 6 hours 20 minutes is 6.33 hours. Going the other way, multiply the decimal part by 60, so 0.25 hours is 15 minutes. Pick one format for the whole timesheet and round only at the end, not on every line.
Minutes to decimal hours chart
Payroll and timesheet systems usually want hours as a decimal, which is minutes ÷ 60. The calculator shows decimal hours to two places. The last column shows four places, so you can see where the two-place rounding comes from.
| Minutes | Decimal hours (2 places) | Decimal hours (4 places) |
|---|---|---|
| 5 min | 0.08 | 0.0833 |
| 10 min | 0.17 | 0.1667 |
| 15 min | 0.25 | 0.2500 |
| 20 min | 0.33 | 0.3333 |
| 25 min | 0.42 | 0.4167 |
| 30 min | 0.50 | 0.5000 |
| 35 min | 0.58 | 0.5833 |
| 40 min | 0.67 | 0.6667 |
| 45 min | 0.75 | 0.7500 |
| 50 min | 0.83 | 0.8333 |
| 55 min | 0.92 | 0.9167 |
So 7 hours 45 minutes is 7.75 hours, and 7 hours 20 minutes is 7.33 hours. Multiples of 6 minutes, such as 6, 12 or 18 minutes, give exact tenths: 0.1, 0.2 and 0.3 of an hour.
Subtracting an unpaid break
The calculator measures the whole span between two times and does not know about breaks. Take them off afterwards. For a shift from 8:45 AM to 5:15 PM, the tool shows 8 hours 30 minutes, or 8.50 decimal hours. Subtract a 30-minute lunch (0.50) and the hours to pay are 8.00. With two breaks, add them up first: 15 + 15 + 30 minutes = 60 minutes = 1.00 hour. To total a week, work out each day here and add the decimal figures.
Midnight, noon and daylight saving time
- 12 AM or 12 PM? In the 12-hour time picker, 12:00 AM is midnight at the start of the day and 12:00 PM is noon. Underneath, the browser always stores the time in 24-hour form, where midnight is 00:00 and noon is 12:00.
- Shifts over a clock change. The calculator works with clock readings and does not know about daylight saving time. On the night clocks go forward one hour, a 10 PM to 6 AM shift is 7 hours of actual time, but the tool shows 8. On the night clocks go back, the same shift lasts 9 hours, and the tool still shows 8. Adjust by the hour yourself on those nights.
- Longest span. With the next-day box ticked, the longest result is just under 48 hours. For spans of several days, use the Date Calculator.
Elapsed time calculator: examples
Elapsed time is the clock time that passes between a start and an end. Enter both times, tick the next-day box if the end is after midnight, and read the result in hours and minutes and in decimal hours.
| Start | End | Break | Elapsed time | Decimal hours |
|---|---|---|---|---|
| 9:15 AM | 5:45 PM | None | 8 h 30 min | 8.50 |
| 10:00 PM | 6:00 AM (next day) | None | 8 h 0 min | 8.00 |
| 7:30 AM | 4:00 PM | 30 min | 8 h 0 min | 8.00 |
| 8:00 AM | 12:20 PM | None | 4 h 20 min | 4.33 |
Which time calculator do I need?
- Time between two clock times: use this elapsed time calculator.
- A weekly timesheet or time card: use the Hours Calculator.
- Add or subtract hours and minutes: use the Duration Calculator.
- Days between dates: use the Date Calculator.
Frequently asked questions
Check "End time is the next day" if the end time is earlier in the clock than the start time — for example, a 10:00 PM to 6:00 AM shift. The calculator then adds 24 hours to the end time before computing the difference.
Yes — enter times using the browser's native time picker, which handles AM/PM (or 24-hour format, depending on your device's settings) for you.
Those two work with calendar dates (years, months, days between two dates). This tool works with clock times within a day — hours, minutes, and seconds between two times, like a work shift or a race split.
Divide the minutes by 60 and add the result to the hours. 45 divided by 60 is 0.75, so 7 hours 45 minutes is 7.75 hours. For 7 hours 20 minutes, 20 divided by 60 is 0.333, so it is about 7.33 hours when rounded to two places.
Not in one step. It measures one start time and one end time at a time. Enter each shift separately, note the decimal hours shown for each one, then add those figures together. Adding decimal hours is simpler than adding hours and minutes, because there is no carrying over at 60.
The calculator treats both times as being on the same day, finds that the end comes before the start, and shows zero rather than a negative number. Tick End time is the next day and it adds 24 hours to the end time, giving the correct overnight duration.
Subtract the start time from the end time. If the end is after midnight, count it as the next day. For example, 9:15 AM to 5:45 PM is 8 hours 30 minutes, or 8.5 hours.
Tick the next-day option so the end time is treated as the following day. 10 PM to 6 AM then gives 8 hours.