PTO Accrual Calculator: Project Your Paid Time Off Balance

Project accumulated PTO balance over time given an accrual rate, pay frequency, and optional cap.

PTO accrual sounds like simple addition until a cap and a mid-year vacation both land in the same pay period — does the cap apply before or after the time off is deducted, and does a used-hours entry attach to the period it falls in or the period it's requested from? This calculator resolves both questions by walking one pay period at a time, applying accrual and cap first, then usage, in that exact order.

How to calculate PTO accrual per pay period

  1. Start from your annual PTO allowance in hours, for example 80 hours, which is two weeks of 8-hour days.
  2. Divide it by the number of pay periods in your year: 80 ÷ 26 biweekly periods = 3.08 hours per paycheck.
  3. Track the balance as starting balance + hours accrued − hours used.
  4. If your employer sets a cap, stop adding once the balance reaches it; accrual only resumes after you take time off.
  5. In the calculator, choose Hours / year to let it do the division, or Hours / pay period if your pay stub already lists a per-period rate.

PTO accrual by pay frequency

Accrual and the cap happen before usage is ever subtracted

Each pay period, the balance first grows by that period's accrual — a flat per-period rate, or an annual rate divided evenly across the year's number of pay periods — and only after that addition is applied does the cap get checked. If the accrual would push the balance past the cap, the period is marked capped and only the room actually available is credited, not the full accrual amount silently clipped after the fact on a display layer.

Usage entries are subtracted after that period's accrual and cap step, never before — which matters because a vacation taken in the same period new time accrues doesn't retroactively block that period's accrual from counting, but it does reduce the balance the following period starts from.

Converting PTO hours to days

Balances are tracked in hours but leave is planned in days, so divide hours by the length of your normal workday. At 8 hours a day, 20 hours is 2.5 days and 120 hours is 15 days; at 7.5 hours a day the same 120 hours covers 16 days.

The calculator reports every balance in hours only, so do this conversion yourself when you check whether a planned trip is covered.

Semimonthly isn't just 'twice a month, arbitrarily'

Weekly and biweekly schedules step forward by a fixed number of days from your start date, and monthly keeps the same calendar day-of-month each period. Semimonthly is handled differently: periods anchor to the 15th and the last calendar day of each month, which is the common real-world payroll pattern, rather than an arbitrary fixed interval based on whatever day happened to be your projection's starting point.

A used-hours entry lands on exactly one period, deterministically

Usage entries are sorted by date and consumed through a single running pointer as the projection steps forward, so each entry attaches to the first pay period whose date falls on or after it — never applied twice if two periods' windows could plausibly overlap it, and never silently skipped if several usage entries land close together.

That deterministic placement means moving a usage entry's date by a day or two can shift which pay period absorbs it, particularly right around a period boundary — worth double-checking against your actual pay calendar if a projected balance looks off by exactly one accrual's worth around a specific date.

Why tracking accrued PTO matters

A projection tells you whether a vacation will be covered on the date you actually take it, not just on the date you book it. It also shows the period where a cap starts holding your balance flat, which amounts to lost time off if you keep working without taking leave.

Accrued time can matter when you leave a job, too. Some states, California among them, treat earned vacation as wages that must be paid out at separation, while many others leave payout to the employer's written policy, so check your state's rules and your handbook before counting on it.

What gets rejected before a projection runs

What this projection doesn't know about your actual policy

It has no concept of accrual tiers that increase with tenure, carryover limits that differ from the ongoing accrual cap, use-it-or-lose-it forfeiture dates, or separate sick-leave versus vacation-leave buckets — all common features of real employer PTO policies that this single-bucket, single-rate model doesn't represent.

It also cannot show borrowing against future accrual. If a usage entry is larger than the balance available that period, the balance stops at zero instead of going negative, so a shortfall shows up as a zero row rather than as a deficit.

Your actual pay stub and HR system are the authoritative record of your real PTO balance; treat this projection as a planning tool for anticipating future balances under a simplified version of your policy, and confirm any number that matters against your employer's actual policy documents or HR representative before relying on it.

Questions people ask about PTO Accrual Calculator

If I use PTO in the same period it accrues, does the accrual still count?
Yes. Accrual and the cap are applied first for that period, and usage is subtracted afterward, so a vacation taken in the same period new time accrues doesn't cancel out that period's accrual. It does, however, reduce the balance the next period starts from.
Why did my accrual show as less than my normal per-period rate?
That happens when the cap is close to being reached — the projection only credits whatever room is actually available under the cap that period, marks the period as capped, and never lets the balance exceed the limit you set, rather than crediting the full rate and clipping the display afterward.
How does semimonthly scheduling actually work here?
Semimonthly periods anchor to the 15th and the last day of each calendar month, matching how most real semimonthly payroll runs, rather than stepping forward by a fixed number of days from whatever date you happened to start the projection on.
Does this account for PTO caps that change with my tenure or separate sick-leave buckets?
No. It models one accrual rate and one cap applied to a single balance for the whole horizon — tenure-based accrual tiers, separate sick and vacation buckets, carryover limits different from the ongoing cap, and forfeiture deadlines are all real policy features this simplified projection doesn't represent. Check your actual policy or HR team for those specifics.
How many hours of PTO do I accrue per week?
Divide your annual allowance by 52: an 80-hour allowance accrues about 1.54 hours a week and a 120-hour allowance about 2.31. If your employer accrues per hour worked instead, such as one hour for every 30 worked, multiply your weekly hours by that ratio, so 40 hours earns about 1.33.
How many days is 20 hours of PTO?
At a standard 8-hour workday, 20 hours of PTO is 2.5 days. If your normal day is a different length, divide by that instead: at 7.5 hours a day, 20 hours is about 2.7 days, and on a 10-hour schedule it is exactly 2 days.
How do I calculate PTO accrual per pay period?
Divide your yearly PTO hours by the number of paychecks you receive in a year: 52 weekly, 26 biweekly, 24 semimonthly or 12 monthly. For example, 120 hours a year paid biweekly accrues about 4.62 hours each period, and choosing Hours / year in the calculator does that division for you.

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Content reviewed 2026-09-27.