PTO Accrual
Calculator

Ask most employees exactly how much paid time off they have banked right now, and you'll usually get a shrug followed by "I think it's around three weeks?" That vagueness isn't laziness — PTO accrual is genuinely confusing. It gets deposited in small, oddly specific increments, on a schedule tied to your paycheck rather than the calendar, using a rate that HR quoted once in an offer letter and that almost nobody re-derives from scratch afterward. Multiply that fuzziness by a cap you may or may not remember correctly, a pay frequency that isn't quite what you assumed, and the fact that hourly and salaried employees are often accruing under completely different rules, and it's no surprise that the number in your head rarely matches the number on your actual pay stub.

This guide exists to close that gap. We'll walk through how the major accrual models actually work, why your pay frequency changes the math more than most people realize, how caps and carryover limits quietly cost people real vacation time every year, and how salaried, hourly, and unlimited-PTO employees should each think about tracking their balance. None of this replaces your employee handbook or your state's specific labor law — but it will make the number on your pay stub make sense.

What "PTO accrual" actually means

Accrual, in a payroll context, simply means paid time off is earned gradually over the course of the year rather than handed to you all at once on January 1st. Instead of starting the year with a lump balance of, say, 15 days, an accruing employee earns a small fraction of that total with every paycheck, every hour worked, or in some structures, every completed month of employment. The appeal for employers is straightforward: it ties earned benefits to actual tenure and hours worked, and it avoids paying out a full year's allowance to someone who leaves after six weeks.

For employees, the practical effect is that your available balance is a moving target that grows steadily rather than a fixed number you can just remember. That's exactly the gap this calculator is built to close — instead of trying to hold the accrual math in your head, you can plug in your actual rate and see where your balance is headed.

The three accrual models you'll actually encounter

Per pay period accrual

This is the most common structure for salaried and many full-time hourly employees. A fixed number of hours is added to your balance on a set schedule tied to payroll — weekly, biweekly, semi-monthly, or monthly — regardless of exactly how many hours you worked that period, as long as you were an active employee. If your policy grants 15 days (120 hours) a year and you're paid biweekly across 26 pay periods, your per-period accrual works out to roughly 4.6 hours each paycheck. The appeal of this model is predictability: your balance grows by the same amount every payday, making it simple to project forward.

Per hour worked accrual

This model is far more common for hourly and part-time employees, and it's also the structure mandated by many state and local paid sick leave laws, which frequently specify a minimum accrual rate such as one hour of paid leave for every 30 or 40 hours actually worked. Unlike per-period accrual, this model ties your earned time directly to hours on the clock, which means a slower week — fewer scheduled shifts, unpaid time off, a reduced schedule — directly slows your accrual that pay period. It's a fairer model for variable schedules, but it also means your balance is genuinely harder to project without knowing your upcoming hours.

Annual lump sum (front-loaded) accrual

Some employers skip incremental accrual entirely and instead grant a full year's allotment of PTO in a single deposit at the start of the year, your anniversary date, or your hire date. This is sometimes called front-loading. The advantage for employees is obvious — the full balance is available immediately rather than dripping in over twelve months — but it usually comes paired with proration rules for employees who start or leave mid-year, since the employer is effectively advancing time off that hasn't technically been earned yet under a strict per-period reading.

Why pay frequency changes the math more than you'd expect

One of the most common sources of confusion in PTO math is assuming "per pay period" always means the same thing. It doesn't, because pay frequency itself varies:

• Weekly: 52 pay periods a year — common in some hourly and union environments.
• Biweekly: 26 pay periods a year, paid every two weeks — the most common structure in the U.S. private sector.
• Semi-monthly: 24 pay periods a year, paid on fixed calendar dates like the 15th and last day of the month.
• Monthly: 12 pay periods a year — common for some salaried and government roles.

Biweekly and semi-monthly are the two that trip people up most, because they sound almost interchangeable but produce meaningfully different math. Biweekly pay happens every two weeks regardless of the calendar, which means twice a year you'll get three paychecks in a single month instead of two — and if your PTO accrues per pay period, that means two "extra" accrual events a year compared to a semi-monthly schedule with a fixed 24 periods. If your employer quoted you an annual PTO total without specifying which schedule that total assumes, converting it to a per-period rate using the wrong frequency will leave your projected balance quietly wrong all year.

Converting an annual PTO allowance into a per-period rate

Most offer letters and handbooks state PTO as an annual figure — "15 days a year," "three weeks," "120 hours." Turning that into the per-period rate your payroll system is actually using is simple division once you know your pay frequency: annual hours divided by pay periods per year. Fifteen days (120 hours) divided across 26 biweekly periods works out to about 4.62 hours per paycheck; the same 120 hours divided across 24 semi-monthly periods works out to exactly 5 hours per paycheck. Both add up to 120 hours over a full year, but they arrive at different rates and different intermediate balances throughout the year, which matters if you're trying to plan a specific trip mid-year rather than just checking your total at December 31st.

Salaried versus hourly: two different accrual realities

Salaried, exempt employees are typically accrued on a straightforward per-pay-period basis, since their compensation itself isn't tied to hours worked in the first place — a fixed hours deposit every paycheck mirrors how the rest of their pay already works. Hourly, non-exempt employees are a different story. Many employers tie their PTO or sick leave accrual directly to hours actually worked, both because it's administratively consistent with how the rest of their pay is calculated and because, in many jurisdictions, it's what local paid sick leave law actually requires.

The practical upshot is that two employees with the identical stated "accrual rate" on paper can end up with meaningfully different real balances by mid-year if one is salaried and accruing a flat amount every paycheck while the other is hourly and accruing only against hours genuinely worked, including any reduction from unpaid absences, reduced schedules, or a slow season.

Proration for new hires and partial years

Very few employees start on January 1st, which means most PTO accrual in someone's first calendar year is prorated. Under a per-period model, proration is usually simple: accrual just begins with your first paycheck and continues on the normal schedule, so a June hire naturally ends the year with roughly half the annual allotment rather than the full amount, without any special calculation needed. Front-loaded, lump-sum policies require more deliberate proration, since granting a full year's balance to someone who joined in October would hand them the same benefit as someone who worked the entire year — most employers instead calculate a fractional grant based on months remaining in the year, or delay the first lump grant until an anniversary date.

Accrual caps: the ceiling most people don't check

A large share of PTO policies include a maximum accrual cap — a ceiling on the total balance you're allowed to hold at any given time. Once your balance reaches that number, accrual effectively pauses; you don't lose the hours you've already earned, but you also stop earning new ones until you use enough PTO to drop back below the cap. This is different from, and often confused with, a separate carryover cap, which specifically limits how many hours you're allowed to roll over from one calendar year into the next, regardless of what your running balance looked like during the year.

Caps exist primarily as a financial liability control for employers — PTO balances are typically recorded as an accrued liability on the company's books, since in many states that time represents a genuine future payout obligation, so an uncapped balance is an uncapped, growing liability. For employees, the practical risk is straightforward: if you consistently accrue faster than you use PTO, you can quietly hit your cap, stop earning new hours for weeks or months, and effectively forfeit accrual you would otherwise have received — which is exactly the scenario this calculator's cap-forecasting feature is built to flag ahead of time rather than after the fact.

Use-it-or-lose-it policies and why they vary so much by state

Whether accrued PTO can simply expire at year-end, whether it must roll over, and whether unused time must be paid out when someone leaves are all governed by a patchwork of state law rather than any single federal standard, since there is no federal law in the United States requiring private employers to offer paid vacation at all. Some states treat earned, accrued PTO as a form of already-earned wages once it's on the books, which restricts or outright bans forfeiture policies and generally requires payout upon termination. Other states give employers considerably more latitude to set expiration dates, carryover limits, or forfeiture clauses in their written policy, as long as that policy is clearly communicated in advance.

Because this variation is so significant — and can also depend on city-level ordinances layered on top of state law — this calculator intentionally does not attempt to apply any specific jurisdiction's legal requirements. It models whatever cap and carryover assumptions you enter, and it's on you (or your HR department) to confirm what your specific state and employer actually allow.

Unlimited PTO: why the math stops applying

Unlimited or "flexible" PTO policies have grown more common, particularly among salaried, exempt roles at larger employers, and they work fundamentally differently from every model discussed above. There's no accrual rate to calculate and typically no balance to track at all, since time off isn't earned incrementally — it's simply requested and approved (or not) against business needs. This also means there's generally no payout obligation at termination, since nothing was ever formally accrued as a wage liability in the first place, which is one of the underappreciated financial incentives for employers adopting these policies.

Research and reporting on unlimited PTO policies has repeatedly surfaced a counterintuitive pattern: without a visible, countable balance creating a natural nudge to use earned time, employees under unlimited policies often take roughly the same amount of time off as they did under a traditional accrual system — sometimes less — rather than meaningfully more. If your employer offers unlimited PTO, this calculator won't have anything to project for you, but it's worth treating the absence of a hard number as a reason to be more deliberate about scheduling time off, not less.

Cash-out and payout at termination

When employment ends, what happens to an unused, accrued PTO balance again depends heavily on state law and your employer's written policy. In states that treat accrued PTO as earned wages, employers are typically required to pay out the full remaining balance in the final paycheck, calculated at the employee's current rate of pay. In states without that requirement, employers may lawfully include a forfeiture clause in their policy, meaning unused time simply disappears upon separation rather than converting to a payout, provided the policy was clearly documented and communicated.

This is one of the more consequential pieces of PTO math to understand well before you're planning a departure, since the difference between a payout and a forfeiture policy can represent a meaningful amount of money — and unlike routine accrual, it's not something you want to discover for the first time on your way out the door.

Common PTO tracking mistakes

Assuming your quoted "annual" rate matches your actual pay frequency. As covered above, the same annual allotment produces different per-period math on a biweekly versus semi-monthly schedule, and mixing the two up compounds into a real error by mid-year.

Confusing the accrual cap with the carryover cap. These are frequently two separate numbers in the same policy, and assuming they're identical can lead to an unpleasant surprise every January.

Not accounting for reduced hours under an hourly accrual model. If your PTO accrues per hour worked, any stretch of reduced hours, unpaid leave, or a slow season will show up as slower accrual, not just slower pay.

Forgetting to re-check the math after a raise, promotion, or tenure milestone. Many policies increase the accrual rate at set tenure milestones — one, three, or five years, for example — and forgetting to update your assumed rate will leave your own projection running behind your actual balance.

Building a habit around checking your balance

The single most reliable way to avoid losing PTO to a cap, a carryover limit, or an expiration date is simply checking your real balance against your policy's rules on a regular cadence — quarterly is a reasonable rhythm for most people — rather than only thinking about it when a specific trip comes up. Pair that check with a rough sense of your accrual rate, and it becomes far easier to plan time off proactively around your actual trajectory instead of reactively once a cap warning email lands in your inbox, if your employer even sends one.

How this calculator's numbers work — and their limits

The figures above are calculated using standard accrual math applied to whichever method, rate, and pay frequency you select, projected forward across your chosen timeline, and checked against the cap you enter, if any. It does not connect to any payroll system, does not know your specific employer's exact policy language, and does not apply any particular state's use-it-or-lose-it or payout rules, since those vary too widely to generalize responsibly in a private, browser-based tool. What it reliably does is apply the underlying accrual math consistently and completely, including surfacing a cap risk that's easy to miss when you're only glancing at a balance number on a pay stub.

The most useful way to use this tool is as a planning aid: confirm your actual rate and cap against your handbook or HR portal, run the projection, and use the timeline to decide when to schedule time off well before you're at risk of hitting a ceiling or running into a year-end deadline.

Putting it all together

PTO accrual isn't complicated math, but it's math that's easy to get subtly wrong when the inputs — your true accrual rate, your actual pay frequency, and whatever cap applies — aren't all lined up correctly in your head at once. Understanding the difference between per-period, per-hour, and lump-sum accrual, knowing whether your state treats earned PTO as a protected wage, and keeping half an eye on your cap and carryover limits are the difference between paid time off you actually use and hours that quietly expire before you ever get around to booking the trip.

Use the calculator above to run your specific numbers, check your projected balance against your cap, and treat the timeline as a nudge to schedule time off well before any deadline creeps up on you — then confirm the details against your own employee handbook or HR portal before making any final plans.