How Many Hours Between Two Times?
Subtract the start time from the end time, then take off any break. 2 PM to 5 PM is 3 hours, and 10 PM to 6 AM with a 30-minute break is 7.5 hours.
To find the hours between two times, subtract the start time from the end time, and add 24 hours if the end time reads earlier on the clock than the start. So 2 PM to 5 PM is 3 hours, and 10 to 2 is 4 hours whether you mean 10 AM to 2 PM or 10 PM to 2 AM.
If you're counting time worked, take any unpaid break off at the end. The harder spans are the ones that cross noon or midnight and the ones with minutes that don't line up, and each has its own section below.
Both times on the same side of noon
Subtract the hours, then the minutes. 2 PM to 5 PM is 5 − 2 = 3 hours, and 8:15 AM to 11:45 AM is 3 hours 30 minutes.
When the end minutes are smaller than the start minutes, borrow an hour. Here is 9:40 AM to 11:15 AM:
- Rewrite 11:15 as 10:75, because one hour is 60 minutes.
- Subtract the minutes: 75 − 40 = 35.
- Subtract the hours: 10 − 9 = 1.
The span is 1 hour 35 minutes.
Spans that cross noon
The clock numbers start over after 12, so 2 − 10 gives you nothing useful for 10 AM to 2 PM. Either of these two methods works.
Count to noon, then past it. 10 AM to noon is 2 hours and noon to 2 PM is 2 more, which makes 4 hours.
Switch to the 24-hour clock. Add 12 to any PM hour from 1 PM on. 2 PM becomes 14, and 14 − 10 = 4. With minutes, 11:30 AM to 3:15 PM becomes 11:30 to 15:15, which is 3 hours 45 minutes.
Noon needs care, because 12 PM already is noon and you add nothing to it. 12 PM to 5 PM is 5 hours. At the other end of the day, 12 AM is midnight, so 12 AM to 5 AM is also 5 hours.
Spans that cross midnight
An end time that reads earlier than the start time falls on the next day. Count to midnight, then count the hours after it.
| Start | End | Up to midnight | After midnight | Total |
|---|---|---|---|---|
| 10 PM | 2 AM | 2 hours | 2 hours | 4 hours |
| 10 PM | 6 AM | 2 hours | 6 hours | 8 hours |
| 11:30 PM | 7:15 AM | 30 minutes | 7 hours 15 minutes | 7 hours 45 minutes |
| 10 AM | 2 AM | 14 hours | 2 hours | 16 hours |
The last row is the other reading of "10 to 2." The 4-hour answer holds when the span stays under 12 hours. If you mean 10 in the morning until 2 the next morning, the answer is 16 hours.
The same clock time on both ends means a full day, so 6 PM to 6 PM the next day is 24 hours.
Clock changes are the one exception to this arithmetic. Where daylight saving time applies in the US, a 10 PM to 6 AM shift on the night clocks go forward in March lasts 7 hours, and on the night they go back in November it lasts 9. The calculator works from clock times and has no date field, so adjust those two nights by hand.
Taking off a break
Work out the whole span first, then subtract the break in minutes.
- 8:30 AM to 5:15 PM is 8 hours 45 minutes. A 45-minute lunch leaves 8 hours.
- 10 PM to 6 AM is 8 hours. A 30-minute break leaves 7 hours 30 minutes.
- 11:30 PM to 7:15 AM is 7 hours 45 minutes. A 30-minute break leaves 7 hours 15 minutes.
Take off only the breaks that are unpaid. The FAQ on the hours calculator has the US federal rule on which breaks count as work time.
Turning minutes into decimal hours
Timesheets and pay calculations often want 7.25 hours where the clock says 7 hours 15 minutes. Divide the minutes by 60 and round to two places.
| 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 |
A decimal is easy to get wrong here, because 7 hours 15 minutes is 7.25 and never 7.15. At $20 an hour, 7.25 hours pays $145.00. Entering 7.15 would pay $143.00, which is $2.00 short.
Getting the same answer from the calculator
The hours calculator has seven rows, Monday to Sunday. Monday to Friday start filled in with 09:00 to 17:00 and a 30-minute break, and Saturday and Sunday start empty. It adds up every filled row, so a single span takes a little setup:
- Enter your start and end time on one row. Your browser may show the fields in 12-hour or 24-hour form.
- Clear both times on the other four filled rows. If you leave them, their hours go into the total.
- Set the break on your row to 0 if you had none, or to your break in minutes.
- Press Calculate.
Enter 23:30 and 07:15 with a 30-minute break and it returns 7.25 total hours. Add a rate of 20 and it returns $145.00. It counts an end time earlier than the start into the next morning, and it reads an end time equal to the start as 24 hours.
Common shifts such as 9 AM to 5 PM have their own pages, each showing the answer with and without a 30-minute break. For a week of clock-ins with overtime and pay, use the time card calculator. To add or subtract lengths of time, such as 3 hours 45 minutes plus 1 hour 35 minutes, use the time duration calculator.