Working out the time between two clock times is simple until minutes and midnight get involved. This hours calculator subtracts a start time from an end time, handles shifts that cross midnight, removes any break, and shows the result in hours and minutes, decimal hours and total minutes — plus pay for the shift if you enter a rate.
How to use the hours calculator
- Enter the start time and end time. For overnight shifts, just enter them as they are — the calculator knows 06:00 comes after 22:00.
- Enter any break to subtract, in minutes.
- Optional: enter an hourly rate to see the pay for this period.
Hours formula
If minutes < 0, add 1,440 (24 hours)
Worked minutes = minutes − break
Decimal hours = worked minutes ÷ 60
Worked examples
A day shift
9:00 AM to 5:30 PM with a 30-minute lunch: 17:30 − 9:00 = 8 h 30 min; minus 30 min = 8 hours. At $18 an hour that's $144.
A night shift
10:00 PM to 6:15 AM: the end is earlier than the start, so add 24 hours. (6:15 + 24:00) − 22:00 = 8 h 15 min, or 8.25 hours.
A morning with odd minutes
7:45 AM to 12:10 PM: 4 h 25 min = 265 minutes = 4.42 hours. At $20 an hour, $88.33.
Common shift lengths
| Shift | Break | Hours worked | Decimal |
|---|---|---|---|
| 8:00 AM – 4:00 PM | none | 8 h 0 min | 8.00 |
| 8:00 AM – 4:30 PM | 30 min | 8 h 0 min | 8.00 |
| 9:00 AM – 5:00 PM | 1 h | 7 h 0 min | 7.00 |
| 7:00 AM – 7:00 PM | 30 min | 11 h 30 min | 11.50 |
| 3:00 PM – 11:00 PM | 30 min | 7 h 30 min | 7.50 |
| 11:00 PM – 7:00 AM | 30 min | 7 h 30 min | 7.50 |
Hours and minutes vs. decimal hours
Payroll systems and spreadsheets use decimal hours, where 7 hours 30 minutes is 7.5. People usually think in hours and minutes. Mixing them is the most common timesheet mistake: 7.30 is not 7 hours 30 minutes, it's 7 hours 18 minutes. To convert, divide minutes by 60; to go back, multiply the decimal part by 60.
Using hours for billing and planning
Freelancers and contractors often bill in fractions of an hour. Common billing increments are 6 minutes (0.1 hour) and 15 minutes (0.25 hour). To bill a 4 hour 25 minute session in 15-minute increments you'd round to 4.5 hours; in 6-minute increments, 265 ÷ 6 = 44.2, so 45 increments or 4.5 hours as well. The same arithmetic helps with planning: if a task takes 2 hours 40 minutes and you have five of them, that's 13 hours 20 minutes, or 13.33 hours — useful for scheduling a week or quoting a job.
Tracking a whole week? Use the Time Card Calculator. Counting days between dates instead of hours? Try the Date Calculator.
Frequently asked questions
How do I calculate hours between two times?
Convert both times to minutes since midnight, subtract, and divide by 60. From 9:00 (540 minutes) to 17:30 (1,050 minutes) is 510 minutes, or 8.5 hours.
How do I calculate hours for an overnight shift?
If the end time is earlier than the start time, add 24 hours to the end time before subtracting. 10:00 PM to 6:15 AM is (6.25 + 24) − 22 = 8.25 hours.
What is 8 hours and 15 minutes in decimal?
8.25 hours. Divide the minutes by 60 and add them to the hours: 15 ÷ 60 = 0.25.
How many hours is 9 to 5?
8 hours. With a 30-minute unpaid lunch it is 7.5 paid hours; with a 1-hour lunch, 7 hours.
Should breaks be subtracted?
Subtract unpaid meal breaks. Short rest breaks are generally paid work time under US federal rules, so leave them in.