How to use the hours calculator
- Enter the start time and end time of a shift.
- Add any unpaid break in minutes. Leave it blank for none.
- Choose Add a shift to include more shifts, for example a split day or several days. You can add up to 10.
- Read the total in hours and minutes, in decimal hours and in total minutes.
Formula
Shift = (end - start) - break
If end is earlier than start, end = end + 24 hours
Total = sum of all shifts
Decimal hours = total minutes / 60
All math is done in whole minutes, so 8 hours 30 minutes is exactly 510 minutes and 8.5 hours.
Worked example: a standard shift
Start 9:00 AM, end 5:30 PM, 30-minute unpaid break. From 9:00 to 5:30 is 8 hours 30 minutes. Subtract the 30-minute break to get 8:00, which is 8.00 decimal hours and 480 minutes.
Add a second shift from 10:00 PM to 2:00 AM. Because 2:00 is earlier than 22:00, the calculator treats it as the next morning, which adds 4:00. The two shifts total 12:00.
Overnight shifts
A shift that ends after midnight is entered with its real clock times. A start of 10:00 PM and an end of 6:00 AM is 8 hours. If the start and end are the same time, the result is zero, not 24 hours. For a full day, use the time duration calculator with dates.
Elapsed hours are not always payable hours
This tool tells you how long a shift lasted after the break you enter. Whether all of that time is payable depends on your employer and the law. Unpaid meal periods, travel time and on-call time follow different rules. Use the result as the starting point, not the final word on pay.
Hours worked in a week
To find a full week, add one row per day or use the time card calculator, which also splits overtime and pay. The weekly total decides overtime under federal rules, so keep your workweek boundaries consistent.
Assumptions and limits
- Times are 24-hour clock times in one time zone. Daylight saving time changes are not applied. Use the time duration calculator when a span crosses a clock change.
- Each shift must be shorter than 24 hours.
- A break longer than the shift is rejected rather than producing negative hours.
Frequently asked questions
How many hours is 8:30 AM to 5:15 PM?
It is 8 hours 45 minutes, which is 8.75 decimal hours. Subtract any unpaid break to find the paid hours.
Can I add several days at once?
Yes. Add one row per shift and read the combined total. For a full week with overtime, the time card calculator is a better fit.
What happens if I leave the break blank?
A blank break is treated as zero minutes. A break you type that is not a number is flagged instead of being guessed.