How to calculate hours worked
Take the end time minus the start time to get the shift length, then subtract any unpaid breaks:
Hours worked = (End − Start) − unpaid break
A 9:00 AM to 5:00 PM shift is 8 hours. Subtract a 30-minute lunch and you have 7 hours 30 minutes — which is 7.5 decimal hours.
Hours and minutes vs. decimal hours
Clocks show hours and minutes, but payroll runs on decimal hours — minutes divided by 60. Fifteen minutes is 0.25, thirty is 0.5, forty-five is 0.75. Multiply the decimal total by your hourly rate to get gross pay, before tax and deductions.
Overnight shifts
When the end time is earlier than the start time, the shift crossed midnight. The calculator automatically adds 24 hours, so 10:00 PM to 6:00 AM correctly comes out as 8 hours.
Frequently asked questions
How do I calculate hours worked?
Subtract the start time from the end time, then subtract any unpaid break. For a 9:00 AM to 5:00 PM shift with a 30-minute lunch, that is 8 hours minus 30 minutes = 7 hours 30 minutes, or 7.5 hours in decimal. This calculator handles the math, including shifts that run past midnight.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add them to the hours. 7 hours 30 minutes is 7 + 30 ÷ 60 = 7.5 decimal hours. Payroll systems use decimal hours, so multiply your decimal total by your hourly rate to get gross pay.
Does the calculator handle overnight shifts?
Yes. If the end time is earlier than the start time, the calculator assumes the shift crossed midnight and adds 24 hours. A shift from 10:00 PM to 6:00 AM correctly reads as 8 hours.
Should breaks be deducted?
Deduct unpaid breaks like a lunch period, since they are not working time. Paid short breaks are usually left in. Enter the total unpaid break minutes and the calculator subtracts them from the shift length.
Disclaimer: Gross pay is before taxes and deductions and does not account for overtime rules or rounding policies your employer may apply.