Time Card Calculation Mathematics & Overtime Rules
Standard payroll processing requires deducting unpaid meal periods and converting clock-in / clock-out times from base-60 hours and minutes into decimal format. Under the Fair Labor Standards Act (FLSA), hours worked in excess of 40 in a single workweek are compensated at a minimum of 1.5× the employee's regular hourly rate.
1. Daily Net Paid Hours Equation
Daily Paid Hours=(Time Out − Time In in Minutes) − Unpaid Break Minutes60 Minutes / Hour
2. Gross Pay & Overtime Formula (FLSA Standard)
Total Gross Pay ($)=(Regular Hours ≤ 40 × Base Rate) + (Overtime Hours > 40 × Base Rate × 1.5)
Step-by-Step Calculation BreakdownStep 1: Calculate Daily Paid Hours (8:30 AM to 5:00 PM with 30 min Lunch)Total Shift Duration = 8 hours 30 minutes (510 minutes)
Net Paid Time = 510 − 30 = 480 minutes = 8.00 decimal hours/day
Step 2: Aggregate 5-Day Workweek & Partition Overtime5 Days × 8.50 Hours = 42.50 Total Hours
Regular Hours = 40.00 Hours | Overtime Hours = 42.50 − 40.00 = 2.50 OT Hours
Step 3: Compute Gross Wages (@ $25.00 / Hour)Gross Pay=(40 × $25.00) + (2.5 × $37.50)=$1,093.75 Gross Pay
Decimal Hours Conversion Quick Reference
| Minutes | Decimal Equivalent | Minutes | Decimal Equivalent |
|---|
| 15 min (1/4 hr) | 0.25 hr | 45 min (3/4 hr) | 0.75 hr |
| 30 min (1/2 hr) | 0.50 hr | 60 min (1 hr) | 1.00 hr |