PTO Accrual Calculator

Understanding PTO accrual

Paid time off (PTO) is typically tracked as a balance of hours you can use while still being paid. Many employers add PTO to your bank each pay period (weekly, biweekly, semimonthly, or monthly). When you take time off, those hours are deducted. A projection helps you plan vacations or personal time without accidentally going negative or bumping into policy limits.

How this PTO accrual calculator works

This calculator uses a simple projection model: start with your current PTO balance, add the PTO you expect to earn over a chosen number of pay periods, then subtract the PTO you expect to use in that same window.

• Current balance (hours): what you have right now in your PTO bank.
• Accrual rate per pay period (hours): how many PTO hours you earn each pay period.
• Pay periods to project: how many future pay periods you want to model.
• Expected hours used: how many PTO hours you think you’ll take during the projection window.

Formulas

Projected PTO balance (hours):

B = Bstart + (r × n) − u

• B = projected PTO balance (hours)
• Bstart = current starting PTO balance (hours)
• r = accrual rate per pay period (hours per period)
• n = number of pay periods to project
• u = expected PTO hours used during the projection

Same formula in MathML:

Optional: convert hours to days

If you want the result expressed in days, this page commonly converts using an 8-hour workday:

Days = Hours ÷ 8

If your workplace uses 7.5-hour days, 12-hour shifts, or another standard, adjust the conversion accordingly.

Interpreting your results

The projected balance is a planning estimate. Here’s how to read it:

• Positive projected balance: you’re expected to have PTO remaining after earning and using time in the projection window.
• Near zero: you’re planning to use almost everything you accrue; consider building in a buffer for sick time or unexpected needs.
• Negative: your planned usage exceeds your starting balance plus projected accrual. Some employers allow “borrowing” PTO; many do not. Treat a negative value as a signal to reduce planned PTO use, shorten the projection window, or verify your accrual policy.

Worked example

Suppose you currently have 80 hours of PTO, you earn 5 hours per pay period, you want to project 26 pay periods (a common biweekly year), and you expect to use 40 hours during that time.

1. Accrued PTO over the period: r × n = 5 × 26 = 130 hours
2. Projected balance: B = 80 + 130 − 40 = 170 hours
3. Converted to days (8 hours/day): 170 ÷ 8 = 21.25 days

In this scenario, after taking 40 hours off across the year, you’d still have about 170 hours (about 21.25 days using an 8-hour day conversion).

Common pay schedules and what “rate per pay period” means

Assumptions & limitations

PTO policies vary widely. This calculator provides a straightforward estimate and does not automatically enforce employer-specific rules. Keep these common factors in mind:

• Units: inputs and the main result are in hours.
• Hours-to-days conversion: if days are shown, it typically assumes 8 hours/day. Your workplace may use a different standard.
• Accrual caps: some employers stop accruing once you reach a maximum balance. This model does not cap accrual unless you manually adjust inputs.
• Carryover and “use-it-or-lose-it” rules: annual resets, carryover caps, or forfeiture deadlines are not automatically applied.
• Waiting periods and eligibility: some policies delay accrual or restrict usage for new hires; this estimate assumes you accrue and can use PTO as entered.
• Tiered accrual rates: if your accrual rate changes with tenure, you can run multiple projections (one segment per rate period) and combine the results.
• Proration: mid-year hires, leave of absence, part-time schedules, or unpaid time can change accruals; adjust n and/or r to match your situation.
• Borrowed/negative PTO: some organizations allow borrowing against future accrual; others prohibit negative balances. Treat negative results as a planning warning and confirm your policy.

Tips for more accurate planning

• If you know exact planned days off, convert them to hours and enter them into Expected hours used.
• If you’re close to an accrual cap, consider projecting shorter windows (e.g., 3–6 pay periods) to see whether you’ll hit the cap before a planned vacation.
• If you’re unsure whether your company counts holidays or shutdowns as PTO, confirm with HR or your handbook and update the “used” estimate.