How to Calculate Average Weekly Work Hours
To calculate average weekly work hours, add the actual hours worked during the period and divide by the number of weeks included. Use a consistent period and account for incomplete weeks so the average is meaningful.
Practical timekeeping guide · ShiftHours
Use a clear date range
If you worked 38 hours in Week 1, 42 in Week 2, and 40 in Week 3, the total is 120 hours. Divide 120 by 3 to get an average of 40 hours per week.
This arithmetic assumes all three weeks are included equally and the hours were recorded consistently.
Handle partial weeks carefully
If the date range begins or ends midweek, decide whether to include that partial week and explain the method. Dividing by three calendar weeks when only a few days were recorded can distort the average.
For formal reporting, use the definition and measurement period required by the relevant policy or authority.
Average hours are not overtime rules
An average can help with planning, but it does not establish overtime eligibility. Overtime may be calculated per workweek or under another applicable method. Keep the underlying weekly totals available.
Avoid replacing detailed timesheets with a single average when exact records are required.
Build the total first
Calculate each shift and weekly total before finding the average. The weekly calculator can help total daily shifts.
Use the free ShiftHours work hours calculator to calculate shift length, subtract unpaid breaks, and view decimal hours. For weekly totals, try the weekly calculator.
Worked example: weekly average
Suppose a person records 38 hours in week one and 42 hours in week two. The two-week total is 80 hours; dividing by 2 gives an average of 40 hours per week. Use complete and comparable weeks when calculating an average.
Related resources
Open the work hours calculator · Browse all ShiftHours articles · Decimal hours chart