How to Calculate Total Work Hours and Overtime Pay

Tracking work hours accurately matters for payroll, invoicing, and verifying your paycheck. The rules for when overtime kicks in, how breaks are counted, and how to total up hours across multiple shifts all have specific answers — and getting them wrong can cost you money.

Converting time to decimal hours

Timesheets usually need hours in decimal form. Convert minutes by dividing by 60: 7:45 is 7.75 hours; 9:20 is 9.33 hours. If you worked from 8:30 AM to 5:15 PM with a 30-minute unpaid break, your total is 8:45 − 0:30 = 8:15 = 8.25 hours. The work hours calculator handles this conversion automatically.

Federal overtime rules (US)

Under the US Fair Labor Standards Act (FLSA), non-exempt employees must receive 1.5× their regular rate for all hours over 40 in a workweek. Some states are stricter — California requires daily overtime (1.5× after 8 hours in a day, 2× after 12). Salaried exempt employees are not entitled to overtime regardless of hours worked.

Tracking multiple shifts

Enter each shift's start time, end time, and break duration. The calculator sums all shifts across the week, applies your hourly rate, and separates regular hours from overtime hours — showing you exactly what your paycheck should reflect before you receive it.