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Work Hours Calculator

Hours calculator

How many hours between two times? This hours calculator counts them for you, even past midnight or days apart. Take off a break if you had one.

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How to calculate hours between two times

Subtract the start time from the end time. If the minutes come out negative, borrow an hour (60 minutes). If the end time is earlier than the start, the period crosses midnight: add 24 hours to the end time first. For decimal hours, divide the minutes by 60.

Worked example, 8:40 AM to 5:15 PM:

  1. Write both times in 24-hour form: 08:40 and 17:15.
  2. Minutes: 15 − 40 is negative, so borrow an hour: 75 − 40 = 35 minutes, and 17 becomes 16.
  3. Hours: 16 − 8 = 8.
  4. Answer: 8 hours 35 minutes, or 8.58 hours (35 ÷ 60 = 0.583).

Using 24-hour (military) time

Subtraction is easiest in 24-hour time, because there is no AM or PM to track. Keep morning hours as they are and add 12 to afternoon and evening hours: 1:00 PM is 13:00, 6:30 PM is 18:30. Midnight is 00:00 and noon is 12:00. So 7:15 AM to 3:45 PM becomes 15:45 − 07:15 = 8 hours 30 minutes.

Hours across several days

Count the whole days first, then add the hours on either side. From Monday 9:00 AM to Wednesday 5:00 PM is two full days (48 hours) from Monday 9:00 AM to Wednesday 9:00 AM, plus 8 hours to 5:00 PM: 56 hours in total. Tick "The end is on a different day" above to have the calculator do this.

Hours in common shifts

Before any unpaid break. Night shifts end the next morning.

ShiftHoursDecimal
9:00 AM to 5:00 PM8:008.00
8:00 AM to 4:30 PM8:308.50
7:00 AM to 3:30 PM8:308.50
9:00 AM to 5:30 PM8:308.50
6:00 AM to 2:00 PM8:008.00
7:00 AM to 7:00 PM12:0012.00
7:00 PM to 7:00 AMovernight12:0012.00
10:00 PM to 6:30 AMovernight8:308.50
11:00 PM to 7:00 AMovernight8:008.00

Hours in a day, week, month and year

PeriodCalendar hoursFull-time work hours (40 a week)
Day248
Week16840
Two weeks33680
Average month730.5173.33
Year8,760 (8,784 in a leap year)2,080

The average month is a year divided by 12: 8,766 ÷ 12 = 730.5 calendar hours, averaging leap years, and 2,080 ÷ 12 = 173.33 work hours. For the full method on a timesheet, including breaks and overtime, read how to calculate hours worked.

Adding up a whole week of shifts? The work hours calculator totals seven days at once and works out overtime. To turn the result into payroll format, use the decimal hours converter.

Common questions

How many hours is 9 AM to 5 PM?

8 hours. With a 30-minute unpaid lunch it is 7.5 hours of work, and with a one-hour lunch it is 7 hours.

How do I calculate hours from 7 PM to 7 AM?

Count to midnight, then add the morning: 7 PM to midnight is 5 hours, midnight to 7 AM is 7 hours, so 12 hours in total. The calculator does this for you when the end time is earlier than the start time.

Can I calculate hours across several days?

Yes. Tick "The end is on a different day" and pick both dates. The calculator then counts every hour from the start date and time to the end date and time, for example a 3-day job or a long-haul trip.

Does it handle daylight saving time?

No. It counts clock time, so a night shift on the night the clocks change will be one hour off. Add or subtract an hour by hand for that shift. Payroll usually pays for the hours you were actually there.

Sources

Last checked . General information, not legal or payroll advice. Your employer's policy, contract or state law may differ.

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