How to Calculate Time Card Hours

Basic time-card formula

For each work period, subtract the clock-in time from the clock-out time. Then subtract any unpaid break.

If a shift includes more than one work period, such as a split shift, calculate the periods separately and add them together.

Convert minutes to decimal hours

Payroll calculations often use decimal hours. Divide the minutes by 60 and add the result to the whole hours.

For example, 7 hours 30 minutes is 7.5 hours. But 7 hours 45 minutes is 7.75 hours, not 7.45. This is one of the most common time-card mistakes.

Example workday

Suppose an employee clocks in at 8:15 AM and clocks out at 5:00 PM with a 30-minute unpaid lunch. The elapsed time is 8 hours 45 minutes. Subtracting the 30-minute lunch leaves 8 hours 15 minutes, which equals 8.25 decimal hours.

Totaling a workweek

Calculate each day first, then add the paid hours for the week. Keeping daily values separate makes it easier to review errors, missed punches or unusual breaks.

If overtime rules apply, the threshold and rate depend on the applicable policy and law. A time-card total by itself does not determine every payroll rule.

Overnight shifts

When a shift crosses midnight, the clock-out time is on the following day. A calculator should recognize that 10:00 PM to 6:00 AM is an eight-hour elapsed period rather than a negative duration.

Common time-card mistakes

• Treating minutes as hundredths of an hour.
• Forgetting to subtract an unpaid meal period.
• Subtracting a later clock time from an earlier one without handling midnight.
• Rounding each punch too early and compounding small errors.
• Assuming the time-card total alone determines overtime eligibility.