How PTO accrual works
Paid time off is usually earned a little at a time rather than handed over in one block. This guide explains the methods employers use, the limits they apply, and the small details that decide whether your tracked balance matches your real one.
The accrual methods
The most common approach grants an annual amount and divides it across your pay periods. Hourly policies instead earn time for each hour you work, which suits part-time and variable schedules. A lump-sum policy grants the full year up front. Some employers raise the rate as your tenure grows. The calculator runs all of these from the same inputs.
Pay frequency changes the per-period number
Because per-period accrual divides the annual amount by how often you are paid, the schedule matters. Weekly, biweekly, semimonthly, and monthly pay all produce different per-period figures from the same yearly total — and biweekly (every two weeks) is not the same as semimonthly (twice a month). A 120-hour (15-day) annual grant, for example, works out to about 2.31 hours weekly (÷52), 4.62 hours biweekly (÷26), 5.00 hours semimonthly (÷24), or 10.00 hours monthly (÷12) — the same year, four different per-period numbers. Those figures are rounded for display, so multiplying one back by its period count can land a few hundredths off the annual total — which is exactly why the calculator carries full precision internally and rounds only at the end.
Caps, carryover, and forfeiture
Two different limits often get confused. An annual accrual cap limits how much you can earn in a year, then resets. A maximum-balance cap pauses accrual whenever your balance hits a ceiling and resumes once you use time. Separately, a carryover limit governs how much rolls into the next year, and anything above it may be forfeited — though some states restrict that.
Why precision matters
Rounding a per-period rate and then carrying it across a year drifts away from the intended annual total. The engine keeps full precision internally and rounds only for display, so your year-end balance lands where the policy intends rather than a fraction off.
How this is verified
No federal law requires private employers to provide paid time off, so the accrual mechanics above come from each employer's written policy, while what happens to an unused balance at separation is governed by state law. The calculator's math runs through a single tested module, and the state rules are reviewed against state labor-department guidance and established HR and payroll references before publishing.
For the state-by-state detail, see the payout laws by state reference. This is general educational information, not legal or tax advice — see the disclaimer for the limits of this tool.