How PTO accrual works
Employers hand out paid time off in one of two basic ways. A lump sum policy credits your full annual allowance all at once — usually on January 1st or on your hire anniversary — so the whole balance is available to book right away. Accrualpolicies instead build up your balance gradually, adding a small number of hours every time you get paid. By the middle of the year, an accrual employee and a lump-sum employee with the same annual allowance end up with a similar total, but the accrual employee only ever has access to what they've earned so far.
In the US, accrual tied to the pay cycle is the most common setup, especially for hourly and non-exempt staff: every weekly, biweekly, semimonthly, or monthly paycheck comes with a matching deposit of PTO hours. Some companies instead accrue PTO per hour actually worked, which matters most for part-time or variable-hour employees whose earned time off should scale with their schedule rather than a flat per-paycheck amount. Many employers also apply a waiting period — commonly 60 to 90 days — before a new hire starts accruing, or before accrued hours become available to use.
How to calculate your accrual rate from your annual allowance
If you know your annual PTO allowance in days, you can work out exactly how many hours land in your balance each payday. Start by converting days to hours (days × 8, assuming a standard workday), then divide by the number of pay periods in a year.
Accrual rate = (Annual days × 8) ÷ Pay periods per year
For example, an employee with 15 days of PTO a year (120 hours), paid biweekly (26 pay periods a year), accrues 120 ÷ 26 = 4.62 hoursevery paycheck. Here's how that looks across a few common allowances and pay schedules:
| Annual PTO | Weekly (52/yr) | Biweekly (26/yr) | Monthly (12/yr) |
|---|---|---|---|
| 10 days (80 hrs) | 1.54 hrs | 3.08 hrs | 6.67 hrs |
| 15 days (120 hrs) | 2.31 hrs | 4.62 hrs | 10.00 hrs |
| 20 days (160 hrs) | 3.08 hrs | 6.15 hrs | 13.33 hrs |
If your pay stub already shows a per-paycheck accrual figure, you can skip this step and enter that number directly into the calculator above.
Converting hours to days
This calculator (and most US employers) treats one day off as 8 hours, so it divides your hours balance by 8 to show how many full days off that represents. That assumption holds for a standard full-time schedule, but it won't be accurate for everyone: if you work 10-hour shifts, a "day" of PTO covers 10 hours from your balance, not 8. If you're part-time and work 6-hour days, a day off only costs 6 hours. Keep that in mind and mentally adjust the "days off" figure by dividing your hours by your own typical shift length instead of 8.
Things that affect the real number
This calculator applies a simple, consistent formula, but real PTO balances are shaped by policy details that a formula alone can't capture:
- Accrual caps.Many policies stop your balance from growing once it hits a maximum, so you don't earn any more hours until you use some and drop back below the cap.
- Rollover limits. Some employers cap how many hours can carry over into the next year — anything above that limit may be forfeited, paid out, or lost, depending on the policy and state law.
- Waiting periods.New hires often can't accrue, or can't use accrued hours, until they've completed a probationary period of a set number of days or months.
- Use-it-or-lose-it rules. Some policies require you to use PTO by a certain date each year or lose it. These rules are permitted in some US states and restricted or banned in others.
Because of all this, treat the result as a planning estimate rather than an official figure. The actual number your employer credits you is governed entirely by your specific written PTO policy, so always confirm your real balance on your pay stub or HR system before making plans around it.