Practical guide · ShiftHours
How to Calculate Hours Worked
To calculate hours worked, find the time between the start and end of a shift, then subtract unpaid breaks. The same method works for most straightforward time-card calculations.
Step 1: Record the start and end times
Use the clock-in and clock-out times from your time record. A 24-hour clock can help avoid confusion between AM and PM: 9:00 AM is 09:00, while 5:30 PM is 17:30.
Step 2: Calculate the time between clocks
For a same-day shift, subtract the start time from the end time. From 09:00 to 17:30 is 8 hours and 30 minutes.
Step 3: Subtract unpaid breaks
Subtract only the break time that should be excluded from working time under your circumstances. In the example above, an unpaid 30-minute lunch gives 8 hours net. Paid-break treatment depends on applicable rules and employer policy.
09:00–17:30 = 8h 30m gross. Minus 30m unpaid break = 8h net = 8.00 decimal hours.
Step 4: Convert the result to decimal hours
Divide minutes by 60, then add that fraction to the whole hours. Thirty minutes is 30 ÷ 60 = 0.50, so 7 hours 30 minutes is 7.50 decimal hours.
Common mistakes
- Subtracting an unpaid break twice.
- Mixing up AM and PM.
- Forgetting that an overnight shift ends on the following day.
- Assuming the calculator applies local overtime, tax or rounding rules.
Weekly totals
Calculate each shift separately and add the net minutes. Adding the minutes first avoids rounding each day too early. Use the weekly work hours calculator to total daily shifts.