WORKHOURKIT · TRUST & TRANSPARENCY
Our calculation methodology
Minute precision, overnight shifts, breaks, rounding, and configurable gross-pay estimates explained.
Clock times become integer minutes
A valid clock time becomes hour × 60 + minute. If the end is earlier than the start, we add 1,440 minutes to the end. Equal start and end times are rejected because zero and 24 hours are ambiguous. Shifts must be shorter than 24 hours. We accept 00:00 through 23:59 or explicit AM/PM notation.
Breaks and multiple shifts
Unpaid breaks are subtracted from the elapsed shift. Paid breaks remain included. Breaks must be whole, nonnegative minutes and cannot exceed the shift. Overlapping shifts are rejected, even across midnight. An overnight shift is assigned entirely to its start day; split entries at a reporting boundary if needed.
Weeks and overtime
Weekly and biweekly sheets use seven or fourteen consecutive start days. Biweekly overtime is calculated independently for each seven-day group. Standalone overtime applies the selected threshold once to the entered duration. Thresholds and multipliers are mathematical inputs, not statements about any employment law.
Precision and pay
Decimal hours equal minutes divided by 60. We round the display to two decimal places without rounding the underlying shift duration. Decimal-to-minute conversion rounds to the nearest minute, with positive half minutes rounded up. Regular and overtime gross-pay components are each rounded to cents, then added. No tax, deduction, daily overtime, or premium stacking is modeled.
Clock time is not timezone-aware elapsed time
These calculators intentionally use wall-clock arithmetic. They do not know locations, time zones, or daylight-saving transitions. For a shift spanning a clock change, use verified elapsed durations from your timekeeping record instead.
Quality and corrections
The shared calculation engine is covered by automated tests for parsing, overnight shifts, breaks, overlaps, aggregation, decimal conversion, overtime, and rounding. Automated checks reduce errors but do not make estimates an official payroll record. For a correction, include your inputs, expected result, and calculator name.