PTO Calculation Methodology
This document details the exact mathematical formulas, pay-period constants, date boundary rules, and rounding conventions used across all 8 calculators on PTO Calculator.
PTO Balance Calculation
Used in the PTO Calculator and homepage quick calculator: Remaining PTO = Starting Balance + Accrued - Used + Adjustments. All inputs are measured in hours. Positive or negative adjustments are added to or subtracted from the net total.
Accrual Calculations
Used in the PTO Accrual Calculator: PTO Per Period = Annual PTO Allowance / Annual Accrual Periods. Over a selected date range, users can calculate accrual by Completed Full Periods, Pro-Rata Partial Periods, or Actual Calendar Days Proration. When an Optional Accrual Cap is specified, total accrued hours are capped at min(Uncapped Accrued, Accrual Cap).
Pay Period Calculations
Used in the PTO Per Pay Period Calculator: PTO Per Paycheck = Annual PTO Hours / Pay Periods Per Year. Standard annual pay period counts are strictly defined as Weekly = 52, Bi-weekly = 26, Semi-monthly = 24,Monthly = 12, and Annually = 1. Monthly equivalent is calculated as Annual PTO Hours / 12.
Payout Estimates
Used in the PTO Payout Calculator: Estimated Gross Payout = Unused PTO Hours × Hourly Pay Rate. Results represent pre-tax gross dollar estimates before federal, state, local, or FICA tax withholdings.
Hours to Days Conversion
Used in the PTO Hours to Days Calculator: PTO Days = PTO Hours / Hours Per Workday. Full workdays are computed as floor(PTO Hours / Hours Per Workday), and remaining partial-day hours are computed as PTO Hours - (Full Workdays × Hours Per Workday).
Carryover Calculations
Used in the PTO Carryover Calculator: Year-End Balance = Current Balance + Accrued Before Year-End - Used Before Year-End. After deducting any Optional Expiring Hours, Eligible Carryover = min(max(0, Effective Year-End Balance), Carryover Limit), and Potential Excess = max(Effective Year-End Balance - Carryover Limit, 0).
Prorated PTO
Used in the Prorated PTO Calculator: Under Actual Calendar Days Proration, Prorated PTO = Annual PTO Allowance × (Eligible Calendar Days / Total Benefit-Year Calendar Days), where both start and end dates are counted inclusively and leap years automatically use 366 days. Under Monthly Proration, Prorated PTO = Annual PTO Allowance × (Eligible Months / Total Benefit-Year Months).
Rounding Rules
All intermediate calculations retain full IEEE 754 floating-point precision. Rounding to two decimal places (standard half-up rounding) is applied only at the final display step for hours, days, and US dollar currency amounts.
Assumptions and Limitations
In the PTO Balance Calculator, future accrual forecasting begins strictly at the user-supplied Next Accrual Date to avoid double-counting hours already included in Current PTO Balance. Users can toggle whether an accrual occurring on the Target Date itself is included.