TL;DR: FMLA provides 12 workweeks of leave in a 12-month period, 480 hours for a full-time, 40-hour-a-week employee. Military caregiver leave extends that to 26 weeks in a single 12-month period, combined with any other FMLA leave you take. Your employer picks how the 12-month period is measured, using one of the methods allowed under federal regulations, and that choice determines when your leave "resets." You don't have to take the 12 weeks in one block, either, intermittent leave lets you use it in hours or days at a time. If 12 weeks (or 26) isn't enough, ADA accommodations, state leave laws, or employer policy may cover the gap. Here's exactly how FMLA leave duration works, down to the hour.
"How long is FMLA leave?" sounds like a simple question. The answer is 12 weeks, but how those 12 weeks are calculated, when they reset, how they translate into actual hours if you're using leave here and there, and what happens if 12 weeks isn't enough is anything but simple. This guide covers the standard 12-week entitlement, the 26-week military caregiver exception, the methods your employer can use to define your 12-month period, how to convert your weeks into hours (especially if you're tracking intermittent leave), and what your options are if you run out of FMLA time before you're ready to return to work.
The Basic Rule: 12 Workweeks
FMLA provides 12 workweeks of leave in a 12-month period. A "workweek" is your regular schedule:
Full-time (40 hrs/week): 12 weeks = 480 hours
Part-time (30 hrs/week): 12 weeks = 360 hours
Part-time (20 hrs/week): 12 weeks = 240 hours
The 12 weeks don't have to be consecutive. You can take FMLA in one continuous block, in blocks of days or hours (intermittent leave), or on a reduced schedule. However you use it, you're drawing down the same 12-week bank, there's no bonus for spreading it out and no penalty for taking it all at once.
FMLA Hours Per Year: Converting 12 Weeks to Hours
If you're taking FMLA in one continuous stretch, you'll probably never think about it in hours, you just count weeks off the calendar until you're back at your desk. But FMLA is legally defined as a bank of hours, not a block of calendar time, and that distinction matters the moment you use leave in pieces instead of all at once.
Here's what 12 weeks of FMLA converts to at different weekly schedules:
Weekly Schedule | 12-Week FMLA Entitlement |
|---|
40 hrs/week (full-time) | 480 hours |
35 hrs/week | 420 hours |
30 hrs/week | 360 hours |
25 hrs/week | 300 hours |
20 hrs/week | 240 hours |
To find your own number, multiply your regular weekly hours by 12. That figure (not "12 weeks") is what your employer actually tracks once you start taking leave intermittently, because a 2-hour doctor's appointment doesn't fit neatly into a "week" of anything.
This is also where part-time employees most often get confused. You still get the full 12-week entitlement (the law doesn't shrink your weeks) but your hours are prorated against your own regular schedule, not a 40-hour baseline. If you work 20 hours a week, your 12 weeks are worth 240 hours, not 480. We break down the full part-time math, including what counts toward your hours in the first place, in FMLA for Part-Time Employees.
If you're already on intermittent leave or expect to be, it's worth tracking your hours as you go rather than trying to reconstruct them later from memory or pay stubs. Our FMLA intermittent leave tracker does the running math for you, and our FMLA calculator can estimate your entitlement and eligibility from scratch.
How the 12-Month Period Is Measured
Your employer chooses how to define the 12-month period your 12 weeks live inside. Federal regulations allow several methods, and this determines when your FMLA leave resets:
Method | How It Works | Example |
|---|
Calendar year | January 1. December 31 | Leave resets every January 1 |
Fixed 12-month period | Any fixed year your employer sets (e.g. Fiscal year, anniversary of hire) | Leave resets on that fixed date |
Rolling forward | 12 months measured from the date you first use FMLA leave | If you first used FMLA on March 15, your year runs March 15. March 14 |
Rolling backward (look-back) | Each time you request leave, your employer looks back 12 months and counts how much FMLA you've used in that window | Every new request recalculates your remaining balance based on the trailing 12 months |
Many employers use the rolling backward (look-back) method, since it's generally seen as the most administratively predictable for the employer and prevents employees from stacking two full 12-week entitlements back-to-back around a single reset date. It's also the most restrictive from an employee's perspective, there's no clean date when your leave balance snaps back to 12 full weeks. Instead, it's continuously recalculated based on what you've used in the trailing year.
Your employer is required to apply one method consistently to all employees and to tell you which one applies, it should be in your employee handbook or leave policy. If you can't find it, ask HR directly rather than assuming. Under the federal regulations governing this (29 CFR § 825.200), an employer that hasn't clearly selected and communicated a method is generally required to use whichever measurement works out most favorably for the employee on that specific request.
How to Calculate Your FMLA Leave
For Continuous Leave
If you take 12 consecutive weeks off, the math is simple: 12 weeks × your weekly hours = your FMLA entitlement.
For Intermittent Leave
Because FMLA is really a bank of hours, intermittent leave changes what "how long" even means. Instead of asking "how many weeks until I'm out of FMLA," you're asking "how many hours do I have left." Track the hours you actually miss:
2 hours for a doctor's appointment = 2 hours of FMLA used
1 day off during a flare-up = 8 hours of FMLA used (for full-time)
3 days off = 24 hours of FMLA used
Only the hours you actually miss count. If you work a partial day, only the missed hours count against your entitlement, not the whole day.
Intermittent leave is common for chronic conditions, recurring treatment like chemotherapy or dialysis, and ongoing family caregiving, and it's the main reason employers convert everyone's entitlement into hours rather than tracking loose weeks. For the full rules on who qualifies, how employers are required to track intermittent leave, and the one category (new-child bonding) where your employer can require a continuous block instead, see our complete guide to intermittent FMLA.
For Reduced Schedule Leave
If you reduce your schedule (e.g. From 8 hours/day to 6 hours/day), the 2 hours/day you're not working count as FMLA leave. Over a 5-day week, that's 10 hours of FMLA used, the same underlying math as intermittent leave, just spread evenly instead of in occasional blocks.
Military Caregiver Leave: 26 Weeks
FMLA provides up to 26 weeks of leave in a single 12-month period to care for a covered service member with a serious injury or illness. For a full-time employee, that's up to 1,040 hours (more than double the standard entitlement) reflecting how much more intensive caregiving leave tends to be.
The 26 weeks includes any FMLA leave taken for other reasons in the same 12-month period. It's a combined limit, not an additional bank stacked on top of your regular 12 weeks. If you already used 4 weeks of standard FMLA earlier in the year and then need military caregiver leave, you have 22 weeks left, not a fresh 26.
Military caregiver leave also uses a different 12-month period than your other FMLA leave: it's measured as a single 12-month period starting the first day you take leave for that purpose, regardless of which method your employer otherwise uses for standard FMLA. That's a meaningful difference from the four methods described above, so don't assume your regular reset date applies here.
What If You Need More Than 12 Weeks?
FMLA caps at 12 weeks (26 for military caregiver leave). If you need more time, here are your options:
ADA Leave
The Americans with Disabilities Act may require your employer to provide additional unpaid leave as a reasonable accommodation, beyond FMLA's 12 weeks. There's no fixed cap, it's determined case by case, based on whether the extra leave would create an undue hardship for your employer.
State Law Extensions
Some states provide more than 12 weeks, or combine job protection with a separate paid-leave program:
California: CFRA (12 weeks) + Pregnancy Disability Leave (17 weeks) = up to 29 weeks of protected leave around a pregnancy
Washington: WA PFML provides 12 weeks of paid leave, layered with job protection rules
Oregon: Oregon Paid Leave provides 12 weeks, with OFLA providing separate job-protection provisions
Massachusetts: MA PFML allows up to 20 weeks for your own serious health condition and up to 12 weeks for family leave, capped at 26 combined weeks per benefit year
State rules change often and vary by employer size and program status, so check our FMLA hub or your state's labor department before assuming a specific number applies to you.
Employer-Provided Leave
Some employers offer leave beyond FMLA as a benefit. This is entirely voluntary, they're not required to.
Personal Leave of Absence
You can request unpaid personal leave beyond FMLA. This is at your employer's discretion and typically does not include the same job-protection guarantees as FMLA.
Frequently Asked Questions
How long is FMLA leave?
12 workweeks in a 12-month period. For full-time employees, that's 480 hours. For part-time employees, it's prorated based on their regular schedule.
How many hours is FMLA leave per year?
For a full-time employee working 40 hours a week, the 12-week entitlement works out to 480 hours per year. Part-time employees get a prorated number, multiply your regular weekly hours by 12. If you work 25 hours a week, that's 300 hours. This hours-based math is what actually matters once you're on intermittent leave, since you're drawing down your entitlement in chunks rather than watching whole weeks tick by on a calendar.
Can I take more than 12 weeks of FMLA?
No. FMLA caps at 12 weeks (26 for military caregiver leave). You may qualify for additional leave under the ADA, state law, or your employer's policies.
How is the 12-month FMLA period calculated?
Your employer chooses one of several federally permitted methods: calendar year, a fixed 12-month period, rolling forward from your first use, or rolling backward (look-back) from each new request. The look-back method is common among employers and tends to be the most restrictive for employees, since there's no fixed reset date.
Does FMLA reset every year?
It depends on how your employer measures the 12-month period. Under the calendar year method, yes, it resets January 1. Under a rolling method, your available leave is continuously recalculated based on what you've used in the trailing 12 months, so there's no single reset date.
Can I take FMLA in smaller chunks instead of all at once?
Yes. Intermittent leave lets you use your 12 weeks in separate periods (hours, days, or a reduced schedule) instead of one continuous block, as long as it's medically necessary and supported by your certification. Employers track the hours you actually miss against your total entitlement. See our guide to intermittent FMLA for who qualifies and how to request it.
Does military caregiver leave replace my regular 12 weeks of FMLA?
No, but it absorbs it. The 26-week military caregiver entitlement is a single combined cap for its own 12-month period, any regular FMLA leave you take for another qualifying reason during that same window counts against the 26 weeks. It's not 12 plus 26.
Is FMLA 12 weeks per calendar year or 12 months?
Neither, necessarily , "per year" is shorthand. FMLA guarantees 12 workweeks within a 12-month period, and your employer selects how that period is defined. Only under the calendar-year method does it literally match January 1 through December 31; under the other permitted methods, your 12-month window can start on almost any date.
Do part-time employees get fewer weeks of FMLA?
No. Part-time employees are entitled to the same 12 weeks. What changes is the number of hours those 12 weeks represent, since weeks are calculated against your own regular schedule rather than a 40-hour baseline. See FMLA for Part-Time Employees for the full hours breakdown.
What happens if my employer doesn't tell me which 12-month method they use?
Ask HR directly and check your employee handbook first. Employers are required to apply one method consistently and disclose it. If an employer hasn't clearly established or communicated a method, federal regulations generally require using whichever measurement works out most favorably for the employee on that specific request, so don't assume the least generous option applies before you've confirmed it.
Can I use FMLA leave for two different reasons in the same year?
Yes, but they draw from the same bank of hours. If you use 4 weeks for your own surgery recovery and then need 8 more weeks for a new baby within the same 12-month period, you have 8 weeks left. FMLA doesn't grant a fresh 12 weeks per qualifying reason.
What happens when FMLA runs out?
If you can't return to work after your 12 weeks (or 26, for military caregiver leave), your employer can generally end your job protection and, in some cases, your employment. Before that happens, explore ADA leave, state law extensions, employer-provided leave, or a personal leave of absence.
Key Takeaways
12 workweeks = 480 hours for a full-time employee; part-time entitlement is prorated against your regular schedule
Several methods exist for measuring the 12-month period, ask HR which one your employer uses, since it changes your reset date
Look-back methods are common and offer no clean annual reset, your balance recalculates continuously
Intermittent leave counts in hours, not weeks, only missed time counts against your entitlement
Military caregiver leave = 26 weeks (up to 1,040 hours for full-time employees), combined with other FMLA leave in its own 12-month period
ADA, state law, or employer leave may extend protection beyond 12 weeks
