The Basic Calculation
For each day worked: End time − Start time − Unpaid breaks = Hours worked that day. Sum all days for the weekly total.
Example: Monday 8:45 AM to 5:30 PM, 30-minute unpaid lunch. Hours = (17:30 − 08:45) − 0:30 = 8:45 − 0:30 = 8 hours 15 minutes
Converting Minutes to Decimal Hours
Payroll systems typically use decimal hours (e.g. 8.25 hours, not 8 hours 15 minutes). Divide the minutes portion by 60:
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 15 min | 0.25 | 45 min | 0.75 |
| 20 min | 0.33 | 50 min | 0.83 |
| 30 min | 0.50 | 55 min | 0.92 |
Overtime Thresholds
Overtime rules vary by country:
- USA: Non-exempt employees earn 1.5× for hours over 40 per week (FLSA). Some states (California) also require daily overtime over 8 hours.
- UK: No statutory right to overtime pay, but the average pay must not fall below the National Minimum Wage across all hours worked.
- EU: Working Time Directive caps working time at 48 hours/week averaged over 17 weeks.
Full Week Example
| Day | Start | End | Break | Hours Worked |
|---|---|---|---|---|
| Monday | 8:45 AM | 5:30 PM | 30 min | 8.25 hrs |
| Tuesday | 9:00 AM | 6:00 PM | 30 min | 8.50 hrs |
| Wednesday | 8:30 AM | 4:30 PM | 0 min | 8.00 hrs |
| Thursday | 9:15 AM | 7:00 PM | 45 min | 8.75 hrs |
| Friday | 9:00 AM | 3:00 PM | 0 min | 6.00 hrs |
| Total | 39.5 hrs |
At 39.5 hours, this employee is under the 40-hour US overtime threshold. At an hourly rate of $20, weekly gross pay = 39.5 × $20 = $790.
Part-Time Pro-Rata Calculation
If a full-time role is 37.5 hours/week and a part-timer works 25 hours/week, their pro-rata fraction is 25/37.5 = 0.667. A full-time salary of $45,000/year becomes $45,000 × 0.667 = $30,015/year pro-rata. This same fraction applies to holiday entitlement and other benefits.
The hours calculator below lets you enter start and end times for each day of the week with break deductions, and calculates your total hours, decimal hours, and gross pay automatically.