How PTO accrual math works
Most accrual systems are the same simple machine: a fixed number of hours added every pay period. Multiply by the periods in a year and divide by 8 to get days. The complications are caps, use-it-or-lose-it policies, and what happens to the balance when you leave.
The core formula
Hours accrued per pay period times pay periods per year equals annual accrual. Biweekly is 26 periods, semimonthly is 24, so the same per-period number yields different annual totals. Divide hours by 8 to state it in days.
Common rates, translated to biweekly hours
10 days a year (80 hours) is about 3.08 hours per biweekly period. 15 days (120 hours) is about 4.62 hours. 20 days (160 hours) is about 6.15 hours. If your handbook quotes days per year, this is how it usually shows up on a biweekly paystub.
Caps stop the clock
An accrual cap is a maximum balance: once you hit it, you stop earning PTO until you use some. If your policy has a cap, enter it and the projection here will not grow past it, exactly as your balance would not.
Use-it-or-lose-it depends on your state
Some employers zero out unused PTO at year end. Whether that is legal, and whether accrued PTO must be paid out when you leave, varies by state: California, for example, treats accrued vacation as earned wages that cannot be forfeited. Your handbook and your state’s law control, not this calculator.
Unlimited PTO has no balance, by design
Unlimited policies mean nothing accrues, so there is nothing to pay out when you exit. For some people the flexibility is worth it; just know that an accrued balance is a real dollar asset in payout states and unlimited PTO is not.
