Reduced Rest & Compensatory Rest Calculator
14 CFR 135.267(d) and (e) — standard rest, reduced rest, and compensatory rest obligations. Free, runs in your browser.
Rest begins when the crewmember is released from duty and is no longer subject to the operator's control.
| Rest available | Status | Comp rest required? | Comp rest minimum length |
|---|---|---|---|
| ≥ 10h | Standard | No | — |
| 9.0 – 9.9h | Reduced | Yes | ≥ 11h |
| 8.0 – 8.9h | Reduced | Yes | ≥ 12h |
| < 8h | Illegal | — | — |
Advisory decision support. Compensatory rest lengths shown are the regulatory minimums — operators with stricter GOM or OpSpecs limits must apply those instead. Operational control stays with the certificate holder (14 CFR 135.77).
Frequently asked
When can reduced rest be used under Part 135?
Under 14 CFR 135.267(e), reduced rest below the standard 10-hour minimum (§135.267(d)) may be used only if: (1) the reduced rest is no shorter than 8 consecutive hours, and (2) a compensatory rest period of the required minimum length is scheduled before the assignment commences and begins no later than 24 hours after the reduced rest period began. Reduced rest cannot be invoked after the fact — the compensatory rest must be arranged in advance.
What is the minimum length of compensatory rest?
The compensatory rest length depends on how short the reduced rest period is. If available rest is 9.0–9.9 hours, compensatory rest must be at least 11 consecutive hours. If available rest is 8.0–8.9 hours, compensatory rest must be at least 12 consecutive hours. These are minimums under the FAR floor — an operator's GOM or OpSpecs may require longer.
When must compensatory rest begin?
The compensatory rest period must begin no later than 24 hours after the beginning of the reduced rest period — not 24 hours after the pilot resumes duty. The clock starts from the moment the rest period began (typically the release from prior duty). If the reduced rest started at 22:00 UTC, compensatory rest must begin by 22:00 UTC the following day.
Does the 8-hour floor apply regardless of crew size?
Yes. The 8-hour minimum rest floor under §135.267(e) applies to both one-pilot and two-pilot crews. The flight-time limits differ by crew size (8h vs 10h per 24 consecutive hours), but the rest floor is the same. An operator cannot reduce rest below 8 hours under any circumstance within Part 135 unscheduled operations — approved deviation authority or a Part 117 rest program would be a separate mechanism.
Clearspar tracks reduced rest and flags missing compensatory rest
If a pilot is assigned under reduced rest, the system flags the compensatory rest obligation before the quote is sent — and warns if it has not been scheduled. No reduced-rest assignment goes out without the compensatory window on record.