Your maximum Flight Duty Period (FDP) depends on three things: report time, number of segments, and how many time zones you’re crossing. Plug those into the calculator below and you’ll have your FDP limit in about four seconds — faster than it took you to read this sentence.
That’s it. That’s the tool. Everything else on this page exists to make sure you actually trust the number it gives you.
✈️ FAR Part 117 Duty Calculator
Enter your recent hours to see your remaining legal limits before your next FDP.
Input fields should be report time (local + zulu), number of flight segments, and acclimated theater — the exact variables Part 117 cares about.
How to Use This Part 117 Duty Time Calculator
I've flown red-eyes where the dispatcher's number and my own mental math disagreed by twenty minutes — and twenty minutes matters when you're the one signing the release. That's the itch this calculator scratches.
Three inputs. One number. No complex tables you have to squint at during a layover.
The FAR 117 "30 in 168" Calculator Rule Explained
Here's where most of the free tools out there quietly give up: they'll happily calculate your single-duty FDP and stop, completely ignoring the part of Part 117 that actually trips people up — the cumulative limits.
The rule is simple to state but annoying to track by hand: you are limited to no more than 30 flight-time hours in any 168 consecutive hours, no more than 60 in any 168 consecutive hours (7 days), and 190 in 672 consecutive hours (28 days).
Our calculator runs these checks against your entered duty history, so you're not cross-referencing three different tables on a phone screen at 5 a.m. If a tool only checks a single-day FDP and calls it done, it's giving you half the regulation. We built this one because half a regulation gives you false confidence.
FAR 117 Limits & Airlines
Understanding FAR 117 Table B & The WOCL Impact
Table B sets your maximum FDP based on report time and number of flight segments. The rule of thumb: the fewer segments and the earlier the report time, the more duty hours you're allowed.
These limits are reduced further if you operate inside the FAR 117 WOCL (Window of Circadian Low), which is 0200–0559 in the pilot's acclimated theater. This is the FAA's polite way of saying "your body thinks it should be asleep right now, so we're not letting you fly as long."
Understanding FAR 117 Flight Time (Table A) & Minimum Rest
While Table B governs your total Duty Period (which fluctuates heavily based on segments and the WOCL), Table A strictly caps your actual Flight Time (block-to-block). Under FAR 117.11, the maximum daily flight time for acclimated pilots is straightforward:
| Time of Report (Local) | Maximum Flight Time |
|---|---|
| 0000 – 0459 | 8 hours |
| 0500 – 1959 | 9 hours |
| 2000 – 2359 | 8 hours |
The Minimum Rest Rule:
Regardless of when you fly, per FAR 117.25, all pilots must receive a minimum of 10 hours of rest between duty periods. Crucially, this must include an 8-hour uninterrupted sleep opportunity.
For the exact, legally binding tables regarding segments and unacclimated operations, always refer straight to the source: the FAA's official Part 117 flight, duty, and rest regulation text.
Part 117 Calculator for United, Delta & American Airlines: Do limits apply?
Short answer: yes, but not only these. Part 117 is the federal floor — the absolute legal minimum rest and maximum duty every Part 121 carrier must respect, full stop.
Longer answer: pilots at Delta, United, American Airlines, and most major carriers fly under union contracts (ALPA, APA) that are frequently more conservative than the FAA baseline. This calculator gives you the federal regulatory limit. Your contract may give you less duty time than that. Always check your own carrier's scheduling rules before you treat this number as gospel.
Frequently Asked Questions (FAQ)
A few exist — some paid, some bundled inside ALPA's member tools. This one's free, runs directly in your browser, and needs zero downloads or app-store approval from your IT department. Just bookmark the page and you are good to go.
Your FDP limit is based on your acclimated time, not the local clock at your current position. The FAA assumes your body adjusts to a new theater after 72 hours there. Cross time zones faster than that, and the calculator adjusts your WOCL window accordingly based on your original theater.
Yes. Part 117 applies to all Part 121 domestic, flag, and supplemental operations — international included. Augmented crew and extended-range rules kick in for the longest international legs, which is a separate calculation you must factor in.
Save & Share Your Results
Hit the "Copy Results" button under the calculator to grab your exact FDP and rest numbers instantly. Paste it in your crew WhatsApp group, save it to your phone's notes, or simply screenshot it — whatever gets it in front of the people who need it before push-back.
