How this hours calculator works
The duration between two times is the gap from when you start to when you stop. The simplest reliable method is to convert each clock time into minutes since midnight, subtract the start from the end, and convert the result back into hours and minutes. Working in plain minutes avoids the awkward arithmetic of carrying and borrowing across the 60-minute boundary.
Once you have the total minutes, divide by 60 to get whole hours, and the remainder is the leftover minutes. For payroll you usually want decimal hours instead: divide the leftover minutes by 60, so 15 minutes is 0.25, 30 minutes is 0.5 and 45 minutes is 0.75. If the end time is earlier than the start time, the tool assumes the shift crosses midnight and adds 24 hours so the result is never negative. An optional unpaid break in minutes is subtracted at the end.
Reference note: calculations work to whole minutes and ignore seconds. Times use a 24-hour internal clock; your browser may display the picker in 12-hour or 24-hour format depending on its locale.
Frequently asked questions
- How do I calculate hours between two times?
- Convert both times to minutes since midnight, subtract the start from the end, then divide by 60 to get hours with a remainder of minutes. For example 9:00 to 17:30 is 1050 − 540 = 510 minutes, which is 8 hours and 30 minutes.
- How do I convert minutes to decimal hours?
- Divide the minutes by 60. So 30 minutes is 30 ÷ 60 = 0.5 hours and 45 minutes is 0.75 hours. A duration of 8 hours and 30 minutes equals 8.5 decimal hours, the format most payroll and timesheet systems expect.
- How are overnight shifts handled?
- If the end time is earlier than the start time, the calculator assumes the shift crosses midnight and adds 24 hours. For example 22:00 to 06:00 is treated as 8 hours rather than a negative result.
- How do I subtract a lunch break?
- Enter the unpaid break in minutes in the break field and it is subtracted from the gross duration. A 9:00 to 17:30 span is 8 hours 30 minutes; deducting a 30 minute lunch leaves 8 hours, or 8.0 decimal hours.
- How many hours is 9 to 5?
- From 9:00 AM to 5:00 PM is 8 hours, or 8.0 decimal hours and 480 minutes, before any break. Subtract a 30 or 60 minute lunch to get 7.5 or 7.0 paid hours.
- Does it count seconds?
- No. This calculator works to whole minutes, which is the standard granularity for work hours and timesheets. Times are entered as hours and minutes and the result is rounded to the nearest minute.