Formula
Net working hours = End time - Start time - (Unpaid break minutes / 60)Direct answer
Subtract the unpaid break from the elapsed same-day clock time. NIST maintains the U.S. standard for time interval; this calculator applies only the entered times and does not determine pay or legal entitlement.
Variables and formula
- Start and end time: same-day decimal 24-hour clock times.
- Unpaid break: minutes to remove from elapsed time.
Net working hours = End time - Start time - (Unpaid break minutes / 60)
Reproducible example
From 09:00 to 17:00 with a 30-minute unpaid break, 8 - 0.5 = 7.5 net hours.
Interpretation
The result is a time total. Use the applicable contract, payroll system and local rules for overtime, rounding and paid-break treatment.
Assumptions and limitations
- Start and end are on one local day.
- The break is unpaid and not already excluded.
- Overnight shifts, time zones, pay and legal rules are excluded.
Common mistakes
- Entering an overnight end time as a smaller same-day number.
- Counting a paid break as unpaid.
- Treating a time total as a payroll calculation.
Assumptions
- Start and end are on the same local calendar day.
- The entered break is unpaid and is not already excluded from the clock times.
- Pay, overtime rules, time zones and legal entitlements are excluded.
Sources and methodology
CalcMotive publishes the formula and assumptions so you can decide whether the estimate fits your use case. See our methodology standards.
- Time and Frequency Division; National Institute of Standards and Technology; accessed Aug 10, 2026