How PTO Accrual Works: Per Hour, Per Paycheck or Granted Up Front
Two jobs can both offer "15 days of paid time off" and still give you very different amounts of time off at any given moment. The difference is the accrual method: how the days are earned through the year. Some employers add a little PTO for every hour you work, some add a fixed amount every paycheck, and some put the whole year's allowance in your balance at once. Knowing which one you have tells you how much time you can take in March, what happens if you leave in July, and how to check that your balance is right.
This guide explains the three common methods with the PTO Accrual Calculator. One thing first: PTO rules are set by your employer's policy and, in many places, by local law, which may require minimum leave, regulate carryover or govern what happens to unused time when you leave. The calculator does the arithmetic. Your employment contract or handbook, and your local labor authority, are where the rules live.
Turning "15 days" into hours
Most payroll systems track PTO in hours, so the first step is converting days to hours. Fifteen days at 8 hours a day is 120 hours a year. The calculator's converter goes one step further and works out the per-hour accrual rate that delivers that total on a standard year:
- 15 days × 8 hours = 120 hours of PTO
- 40 hours a week × 52 weeks = 2,080 hours worked
- 120 ÷ 2,080 = 0.0577 hours of PTO per hour worked
The converter rounds the rate to four decimal places. That is precise enough for practical use, but it means a full year at 0.0577 comes to 120.02 hours rather than exactly 120. Your employer's system may use a slightly different rounding, which is one reason small differences between your own calculation and your pay stub are normal.
Method 1: per hour worked
With per-hour accrual, every hour you work earns a fraction of an hour of PTO. It is common for hourly and part-time roles, because it scales automatically with the hours you put in.
At 0.0577 hours per hour, here is what the calculator shows:
| Hours worked | PTO earned | In 8-hour days |
|---|---|---|
| 520 (13 weeks at 40 hours) | 30.00 hours | 3.75 days |
| 585 (13 weeks at 45 hours) | 33.75 hours | 4.22 days |
| 2,080 (a full year at 40 hours) | 120.02 hours | 15.00 days |
The 585-hour row raises a question your policy should answer: do overtime hours earn PTO? Some policies count all hours worked, some count only regular hours, and some count hours paid, which can include holidays and PTO itself. The calculator simply multiplies the rate by whatever hours you enter, so enter the hours your policy counts.
Method 2: per pay period
With per-period accrual, a fixed number of hours is added each paycheck, regardless of the exact hours you worked (for full-time staff, at least). To spread 120 hours over 26 biweekly paychecks, the rate is 120 ÷ 26 = 4.62 hours per paycheck, rounded to two decimals.
- After 6 paychecks: 27.72 hours (3.47 days)
- After 26 paychecks: 120.12 hours (15.02 days)
Again, rounding the rate to 4.62 means the year totals 120.12 rather than 120. On a semimonthly schedule (24 paychecks), 120 hours divides evenly into 5 hours per paycheck, and 24 paychecks come to exactly 120.00 hours.
Per-period accrual is predictable: you can look at a calendar and know your balance. It does not reward extra hours, and for part-time staff some employers prorate the per-period amount.
Method 3: annual grant (front-loaded)
With an annual grant, the year's allowance appears in your balance on a set date, often the start of the year or your work anniversary. In the calculator, choose annual grant and enter 120 hours: the accrued figure is 120.00 hours, or 15 days, on day one.
The obvious advantage is flexibility. You can take a two-week trip in February without waiting months to build the balance. After 13 weeks, a front-loaded employee has 90 more hours available than a per-hour employee earning at the same annual rate, who would have 30.
The trade-offs are policy questions rather than arithmetic ones. If you use the whole grant early and then leave, some employers may treat the unearned part differently from earned time, and whether they can recover it from final pay depends on the policy and local law. If you are on a front-loaded plan and might change jobs mid-year, read the handbook section on leaving before you book the trip.
Comparing the three across a year
| After about a quarter | PTO available |
|---|---|
| Per hour (520 hours worked) | 30.00 hours |
| Per pay period (6 biweekly paychecks) | 27.72 hours |
| Annual grant | 120.00 hours |
By year end, all three land at roughly 120 hours. The difference is timing, and timing is often what matters when you are planning a holiday, starting a new job or deciding when to leave one.
Checking your own balance
If your balance looks wrong, the calculator can help you check it.
- Find your accrual method and rate in your handbook or HR system. If it gives only days per year, use the converter to get an hourly rate, or divide hours per year by your number of paychecks for a per-period rate.
- Find your starting balance and the date it applied from.
- Count the hours worked or pay periods since then, using your pay stubs.
- Enter them, along with any maximum balance your policy sets, and compare the projected balance with your stub.
- Subtract any PTO you have taken in that period, since the calculator does not track usage.
Small differences are usually rounding. A big gap is worth a polite question to HR or payroll, with your workings attached.
A worked check
Say your handbook says 4.62 hours per biweekly paycheck. Your balance was 16 hours on a date ten paychecks ago, and you have taken 24 hours off since. Enter the per-period method, a rate of 4.62, 10 pay periods and a starting balance of 16. The calculator shows 46.20 hours earned and a projected balance of 62.20 hours (7.78 days). Subtract the 24 hours you took and you should see about 38.20 hours on your stub. If your stub shows, say, 30, the gap is roughly two paychecks of accrual, which is a specific, checkable thing to ask payroll about: whether two periods were missed, or whether your policy has a waiting period or a different rate than you thought.
Caps and carryover
Many policies set a maximum balance. Once you reach it, you stop earning until you use some time. The calculator applies a cap if you enter one: accrual stops at the cap, and a balance that is already above it is left where it is rather than cut back. Our guide to what happens when you hit the PTO cap works through examples.
Carryover is a related but different rule: how much unused time rolls into the next year. Some employers allow all of it, some a fixed amount, some none, and in some places local law affects whether unused time can be forfeited at all. The calculator does not model carryover rules; check your handbook and, if in doubt, your local labor authority.
Common questions
Does PTO accrue while I am on PTO?
It depends on the policy. Per-period plans often keep accruing during paid leave; per-hour plans may count only hours worked, or hours paid. Your handbook should say.
I work 37.5 hours a week. Does the converter still work?
Yes. Enter your hours per week and your hours per day, and the converter works out the rate for your schedule. Our guide to part-time PTO covers shorter weeks in detail.
How long until I have a full week off at a new job?
That depends on the method and any waiting period. We work it through in starting a new job: how long until you have earned a week off.
Is PTO worth money when comparing offers?
Yes: more paid days off for the same salary means a higher rate per day worked. The Job Offer Comparison Calculator values each paid day at base salary divided by 260 working days, so offers with different leave can be compared in one figure.
What the calculator does not do
- It does not know your employer's policy or local law. It calculates from the method, rate and cap you enter.
- It does not track PTO you take, holidays, sick leave rules or waiting periods.
- It does not model carryover, payout on leaving or any legal minimum.
- Its results are estimates; your HR or payroll system is the official record.
Pick your method in the PTO Accrual Calculator, enter your rate and hours, and you will know not just how many days you get a year, but how many you have right now.