PTO Accrual Calculator

Biweekly and semi-monthly PTO accrual are different

This is the most common mistake in paid time off math, and it's purely a vocabulary problem. Biweekly means every two weeks: a paycheck every 14 days, which lands 26 times in a 365-day year. Semi-monthly means twice a month, usually on the 15th and the last day, which lands 24 times. People use the two words as if they meant the same thing. Payroll never does.

The gap is 26 ÷ 24, or 8.33%. If your policy grants 4 hours per pay period, biweekly gives you 104 hours a year and semi-monthly gives you 96. That's a whole workday, won or lost by reading the wrong word in a handbook. A calculator with a single "twice a month" option is quietly picking one of the two for you.

One more detail. Since 26 × 14 is 364 days, biweekly payroll drifts by a day each year and now and then produces a calendar year with 27 pay dates. So this tool counts the actual dates between your start and your target instead of dividing an annual figure. An extra period is real hours, and an annual average would hide it.

Three ways employers write the same PTO accrual rate

Handbooks state accrual in whatever unit suited the person who wrote them. You can't convert between those units without knowing your schedule.

• Per hour worked. This is the usual form for hourly staff and the one nearly every US sick leave statute uses, typically one hour earned for every 30 hours worked. It's proportional by construction, so it means nothing until you plug in your weekly hours. Someone at 20 hours a week earns exactly half of what a 40-hour colleague does on identical terms. Overtime hours usually count toward accrual too, which is why a heavy quarter can push your balance ahead of the projection.
• Per pay period, a flat number of hours each paycheck. It's easy to read, and it's where the biweekly/semi-monthly mix-up does its damage, because the annual total depends entirely on how many paychecks there are.
• Per month or per year, which is the salaried convention. Ten hours a month is 120 hours a year no matter how often you're paid, but it turns into 4.62 hours in a biweekly period and exactly 5 in a semi-monthly one. The tool converts through the annual figure, the only common denominator that holds up when you switch.

Full-time in the US is conventionally 2,080 hours a year. A policy of 0.0385 hours per hour worked therefore comes to a hair over 80 hours, or ten days, for someone at 40 hours a week, and to something quite different for anyone else.

The PTO accrual cap is a silent leak

An accrual cap sets a maximum balance. Once you reach it, accrual stops. The hours you would have earned aren't deferred, banked or paid. They're never credited, and no line on your pay stub tells you. This is what separates a useful calculator from a decorative one, and it's why the tool simulates every pay period instead of multiplying once at the end.

A balance at the cap is an open drain. An employee capped at 240 hours who accrues 4 hours biweekly and takes no time off throws away 104 hours over a year. That's thirteen workdays of compensation, earned and then gone. The calculator reports the exact date you hit the cap and the running total lost after it, because that's the number that gets people to change what they do.

Timing matters more than most people expect. Take 40 hours off in January and you open 40 hours of headroom that soaks up five pay periods of accrual. Take the same 40 hours in December and it soaks up nothing, because the cap was already throwing accrual away all year. Same time off, same policy, 40 hours apart. Change the "when they come off" selector to see it.

Carryover, rollover and use-it-or-lose-it are three different policies

A cap limits your balance all year. A carryover rule bites once a year, at the plan year boundary, and it comes in three versions that people describe with the same words:

• With full carryover, the balance crosses the boundary untouched, and the cap is the only real limit.
• With limited carryover, anything above a threshold (40 or 80 hours are typical) is forfeited on day one of the new year, and the rest survives.
• With use it or lose it, the balance resets to zero, and every hour not taken by the deadline is gone.

The plan year doesn't always start in January. Anniversary-based plans, fiscal years starting in July or October, and academic years are all common, and moving the boundary changes which accrual is at risk. That's why the tool asks for the month.

Use-it-or-lose-it is also the policy most likely to be unenforceable where you live. States that treat accrued vacation as earned wages, among them California, Colorado, Montana, Nebraska and Massachusetts, generally ban outright forfeiture while still allowing a reasonable accrual cap. Their logic: a cap stops you from earning more, and it never takes back what you already earned. It sounds like a legal technicality, and it's worth real money.

PTO hours only become days once you pick a workday

Balances are kept in hours and time off is requested in days. The bridge is your daily schedule, and that isn't always eight hours. A compressed four-day week runs 10-hour days. A 37.5-hour week runs 7.5. Part-time runs 4, 5 or 6. Nurses and shift workers run 12.

A 120-hour balance is 15 days at eight hours and 12 days at ten. The balance didn't change. What changed is how much time off you believe you have, and people plan vacations around that belief. The tool asks for your workday length instead of hardcoding it, and shows the answer in both units.

Accrued PTO works differently from a front-loaded grant

Some employers deposit the full annual allowance on day one of the plan year. That's a grant, and it behaves differently from accrual. You can take all of it in February, but if you leave in March, many policies claw back or refuse to pay the unearned part. Accrual runs the other way. You can only spend what has already vested, and what has vested is generally yours.

To model a grant here, set the balance to the full allowance and the accrual rate to zero. Many companies actually run a hybrid: a front-loaded grant that accrues nothing more until the next reset. For that, do the same and set carryover to whatever the reset rule is.

Check your PTO balance against your pay stub, not a blog post

Everything above describes how policies usually work. Yours may differ. Two numbers on your own documents settle it. The accrual line on your pay stub gives the real per-period figure, including any tenure-based step increases. The balance in your HR portal is your true starting point. Enter those two and the projection describes your plan instead of the average plan.

US federal law requires no paid time off at all. The FLSA sets no minimum for vacation, holidays or personal days. Everything you have comes from your employer's policy, shaped by state law. The handbook is the source of truth, and this tool does the arithmetic on whatever the handbook says.

Privacy

Every calculation runs in your browser. Your balance, rate, schedule and planned time off are never uploaded, logged or stored, and there's no account. That matters here, because an accrual balance plus a workweek is a fairly precise description of your job. It shouldn't have to leave your machine to be divided by twenty-six.