How the rolling 12-month period works
Under the rolling backward method, every day an employee takes FMLA leave, you look back exactly 12 months from that day. Whatever FMLA time falls inside that window counts against the 12-week entitlement; anything older has "rolled off" and is available again.
That 12-week entitlement equals 480 hours only if you work a standard 40-hour week (12 × 40). Part-time schedules or compressed workweeks convert to a different hour total — enter your actual hours per week above and the calculator does the conversion for you.
Rolling backward vs calendar year
Employers may choose one of four FMLA year methods: calendar year, any fixed 12-month year, measured-forward, or rolling backward. The rolling method prevents "stacking" 24 weeks back-to-back across a year boundary, which is why most employers use it — and why it's the one that's miserable to track in Excel.
FAQ
How many weeks of FMLA does an employee get?
Up to 12 workweeks in a 12-month period (26 weeks for military caregiver leave). For a 40-hour schedule that's 480 hours; this tool scales it to the schedule you enter.
How do I count intermittent FMLA?
Count the hours actually taken. Add each absence here as its own row — use the hrs/day column for partial days (e.g. 4-hour appointments).
When do used weeks come back?
Under rolling backward, each hour frees up exactly 12 months after it was used. The result panel lists the upcoming free-up dates.
Is my data uploaded anywhere?
No. Everything is calculated in your browser. Close the tab and it's gone.
FMLA rolling period — FAQ
How does the FMLA rolling look-back actually work?
Rolling backward measures 12 months back from each day of leave, not from a fixed anniversary date. Only the leave inside that trailing window counts against the 12-week cap — anything older has already rolled off.
How many FMLA hours do I have left?
Your remaining balance is 12 workweeks minus whatever leave falls inside the current rolling window, converted to hours at your scheduled hours per week. Enter your dates and schedule above and this calculator shows the exact hours and weeks left.
Is FMLA always 480 hours?
Only if you work a standard 40-hour week — 12 weeks × 40 hours = 480 hours. Part-time or longer schedules produce a different hour total, though the legal entitlement is always 12 workweeks.
What's the difference between rolling and calendar-year FMLA?
Employers can pick one of four ways to measure the 12-month period: calendar year, any fixed year, measured forward, or rolling backward. Rolling backward is the strictest for employees, since it prevents stacking two full 12-week blocks back-to-back across a year boundary — which is why most employers use it.
Do FMLA hours expire, or just come back later?
They come back. Once a used hour crosses the 12-month mark under the rolling method, it drops out of the current window and is available again — nothing is permanently lost.
Can my employer switch counting methods?
Yes, but only if the new method applies to all employees at once, with proper notice. If an employer never clearly designated a method, the DOL requires using whichever method benefits the employee most.