Work Hours Calculator

Adding up a shift takes five quick entries. The tool subtracts the start time from the end time, takes off the unpaid break, and turns the answer into decimal hours and pay.

1. Pick your start time and your end time. An end time earlier than the start counts as the next day, so night shifts work.
2. Enter your unpaid break in minutes. A standard lunch is 30 minutes.
3. Enter your hourly rate if you want the pay, or leave it at 0 for hours only.
4. Enter how many shifts you work a week, then press Calculate, or press Enter. The hours appear first and large, with decimal hours, weekly hours and overtime below. Press Reset to clear the form and start over.

The work hours formula is hours worked = (end time - start time - unpaid break) / 60. Times are turned into minutes after midnight, so 9:00 AM is 540 minutes and 5:30 PM is 1,050 minutes. Subtract the start from the end, take off the break, and divide by 60 to get decimal hours.

When the end time is earlier than the start time, 24 hours are added to the end, because the shift crossed midnight. Weekly hours are the shift hours times the shifts per week, and hours over 40 in a week are overtime at 1.5 times the regular rate under the US Fair Labor Standards Act. Our time duration calculator finds the time between any two clock times without the pay math.

A shift runs from 9:00 AM to 5:30 PM with a 30 minute unpaid break, at $25 an hour, five days a week. Here is exactly what the calculator does.

1. Shift length: 5:30 PM - 9:00 AM = 8 hours 30 minutes.
2. Take off the break: 8 hours 30 minutes - 30 minutes = 8 hours.
3. Decimal hours: 480 minutes / 60 = 8.00 hours.
4. Hours per week: 8.00 x 5 = 40 hours.
5. Gross pay: 40 x $25 = $1,000 a week, with no overtime.

As a second check, a night shift from 10:00 PM to 6:00 AM with a 30 minute break is 8 hours minus 30 minutes, or 7.50 hours. The same steps work for any shift, so try your own numbers in the tool above.

Night shifts cross midnight, so the end time looks earlier than the start time. The calculator adds 24 hours to the end time in that case, so a shift from 10:00 PM to 6:00 AM counts as 8 hours, not minus 16. The same rule applies to any shift that ends after midnight.

Payroll works in decimal hours, not hours and minutes. Divide the minutes by 60, so 7 hours 30 minutes is 7.50, 7 hours 45 minutes is 7.75, and 7 hours 15 minutes is 7.25. Writing 7 hours 45 minutes as 7.45 is a common mistake, and it quietly removes 18 minutes of pay per shift.

Under the US federal Fair Labor Standards Act, non-exempt employees earn 1.5 times their regular rate for hours over 40 in a workweek. This calculator splits the week at 40 hours and pays the rest at 1.5 times the rate. A six day week of 8 hour shifts is 48 hours, so 40 hours are regular and 8 hours are overtime.

At $15 an hour, that week pays 40 x $15 plus 8 x $22.50, which is $600 plus $180, or $780. Daily overtime rules in some states, such as California, are not included, and your employer and local law decide what you are actually paid.

The most common mistake is writing minutes as a decimal, so 8 hours 45 minutes becomes 8.45 instead of 8.75. Always divide the minutes by 60, or let the calculator do it. The second mistake is deducting paid rest breaks. Short rest breaks of about 5 to 20 minutes are paid time under federal rules, so only deduct a meal break where you are fully relieved of duty.

The third mistake is forgetting the break entirely, which overstates the shift by the length of the lunch. The fourth is rounding the wrong way. This calculator rounds only at the end, so the pay uses the exact hours, not the rounded figure. Our time calculator adds and subtracts clock times, and our military time converter turns 24 hour times into AM and PM times.