What is an hours calculator?
An hours calculator works out the elapsed time between a start time and an end time. It is useful for payroll, timesheets, work shifts, invoices, and general time tracking where you need both hours and minutes and decimal hours.
How to calculate hours worked
Convert the start and end times into minutes after midnight, subtract the start from the end, then convert the result back into hours and minutes. If the end time is earlier than the start time, treat the end time as the next day.
How to subtract lunch or break time
First calculate the full shift length, then subtract the break duration in minutes. For example, 9:00 AM to 5:00 PM is 8 hours. With a 30-minute break, the paid time is 7 hours 30 minutes.
How to convert hours and minutes to decimal hours
Divide the minutes by 60 and add the result to the whole hours. For example, 7 hours 15 minutes = 7.25 hours, 40 hours 24 minutes = 40.40 hours, 30 minutes = 0.50 hours, and 45 minutes = 0.75 hours.
How overnight shifts are calculated
If the end time is earlier than the start time, the calculator assumes the shift continues into the next day. For example, 22:00 to 06:00 is treated as an overnight shift lasting 8 hours.
Time clock rounding explained
Some employers round clock-in and clock-out times to the nearest 5, 6, or 15 minutes. Rounding changes the recorded start and end times before the duration is calculated, so it can slightly increase or decrease decimal hours.