FMCSA Hours-of-Service Compliance Calculator

How this calculator works

Hours-of-service compliance under 49 CFR Part 395 is governed by four simultaneous numeric limits: the 11-hour driving limit, the 14-hour on-duty window, the 30-minute break after 8 driving hours, and the 60-hour 7-day or 70-hour 8-day weekly cycle. Every legal driving shift has to satisfy all four at once. This calculator takes the four hour counters as inputs, applies the algebra of each limit, and returns the headroom remaining on each — plus the binding limit (the one that will bite first) and the next-permissible-drive timestamp computed from the end of the last qualifying rest period.

The calculation proceeds in four parallel paths. First, the per-shift drive headroom: 11 minus the driving hours used today. Second, the per-shift on-duty headroom: 14 minus the on-duty hours used today, where on-duty includes driving plus pre-trip and post-trip inspection, fueling, loading, and other compensated work. Third, the 30-minute break check: 8 minus the cumulative driving hours since the last qualifying break; the break becomes mandatory when this counter reaches 8. Fourth, the weekly cycle: 60 minus the on-duty hours over the most recent 7 days for carriers not operating every day, and 70 minus the on-duty hours over the most recent 8 days for carriers operating every day; the effective weekly drive headroom is the smaller of the two.

The hours-until-forced-rest output is the smallest of the drive headroom, the on-duty headroom, and the weekly headroom — whichever limit hits zero first determines when the driver must stop driving. The compliance status returns one of four values: compliant (all four limits leave headroom and the break is satisfied), break-required (the 8-hour driving counter has reached its threshold), limit-reached (less than 30 minutes of driving remain), or rest-required (one of the four limits is exhausted and the driver may not drive again until a qualifying rest period). The next-permissible-drive timestamp adds 10 hours to the supplied last-rest-end timestamp for a standard reset, 8 hours for an 8/2 sleeper split, or 7 hours for a 7/3 sleeper split.

The four governing HOS limits under 49 CFR § 395.3

The HOS framework is built from four limits that must be satisfied simultaneously. Compliance is the intersection of all four, not the satisfaction of any one.

11-hour driving limit (49 CFR § 395.3(a)(3)). A property-carrying CMV driver may drive at most 11 hours after 10 consecutive hours off duty. The clock starts on the first minute the truck is in motion or moving on a public roadway after the rest period and ends when the cumulative driving hours reach 11. Non-driving on-duty time (fueling, loading) does not count against the 11-hour limit but does count against the 14-hour window. The 11-hour figure is the maximum driving time per shift, period — it cannot be extended for normal operations, only by the adverse-driving exception under 49 CFR § 395.1(b)(1) (which adds up to 2 hours for unforeseen conditions).

14-hour on-duty window (49 CFR § 395.3(a)(2)). The 11 driving hours must fall within a 14-hour window that begins when the driver first goes on duty after the 10-hour rest. The window is a wall clock, not a counter — it does not pause for meals, fueling, customer dwell, or any other interruption that keeps the driver on duty. Once 14 hours have elapsed from the start of the shift, the driver may not drive again until the next 10-hour rest period (or qualifying sleeper-berth split). The 14-hour window is the limit that creates the strongest incentive to take a sleeper-berth split, because the split allows the driver to extend the effective on-duty period beyond a single 14-hour wall clock.

30-minute break after 8 driving hours (49 CFR § 395.3(a)(3)(ii)). After 8 cumulative hours of driving without an interruption of at least 30 minutes, the driver must take a 30-minute non-driving break before driving again. The 2020 HOS rule change clarified that the break may be off-duty, sleeper, or on-duty-not-driving — so a customer dock wait, a fueling stop, or any other non-driving activity of at least 30 continuous minutes satisfies the requirement. The clock measures driving time, not total elapsed time. After a qualifying break, the 8-hour counter resets to zero and the driver may drive again up to the 11-hour daily limit.

60/70-hour weekly cycle (49 CFR § 395.3(b)). A driver may not drive after accumulating 60 on-duty hours in 7 consecutive days (for carriers not operating every day of the week) or 70 on-duty hours in 8 consecutive days (for carriers operating every day). The choice between the 60/7 and 70/8 cycles is the carrier's election, not the driver's. The cycle rolls — each day, the on-duty hours from 8 days ago drop off the rolling window and the current day's on-duty hours come in. The cycle resets to zero only via the 34-hour restart provision under 49 CFR § 395.3(c), which becomes available after 34 consecutive hours off duty.

The sleeper-berth split under 49 CFR § 395.1(g)

The sleeper-berth split is the most operationally important flexibility in the HOS framework, because it lets a driver extend the effective on-duty period beyond a single 14-hour wall clock without violating any limit.

The standard rule is 10 consecutive hours off duty before resuming driving. The split rule, under 49 CFR § 395.1(g), lets the driver divide the 10 hours into two periods: a long period in the sleeper berth and a short period off duty or in the sleeper. Two qualifying split structures: the 8/2 split (8 consecutive hours in the sleeper plus 2 consecutive hours off duty or sleeper) and the 7/3 split (7 consecutive hours in the sleeper plus 3 consecutive hours off duty or sleeper). The two periods do not have to be consecutive and can be taken in either order. Neither period counts against the 14-hour driving window — that is the operational value of the split.

The arithmetic works out in the driver's favor when a customer schedule creates a natural mid-shift break. For example: the driver completes a 7-hour driving shift, takes a 3-hour off-duty break during a customer unload, drives 4 more hours, and then takes a 7-hour sleeper period. Without the split, the driver would have used 14 hours of the on-duty window (7 driving plus 3 off-duty plus 4 driving) and could not drive again until the next 10-hour reset. With the 7/3 split, the 3-hour off-duty break does not count against the 14-hour window — so the effective on-duty window covers only the 7 plus 4 hours of driving plus whatever non-driving on-duty time the driver logged, leaving room for more driving after the 7-hour sleeper period.

The 8/2 split is the more common choice because the 8-hour sleeper period is closer to a normal sleep cycle. The 7/3 split is useful when a 3-hour customer dwell or yard wait creates a natural off-duty window the driver wants to convert into qualifying split time rather than burning the 14-hour wall clock.

What the inputs mean and how to source them

The seven inputs map directly to fields the driver's electronic logging device (ELD) already maintains under 49 CFR Part 395 Subpart B. The ELD is the legally controlling record; this calculator is a planning overlay that pulls the same numbers and runs the headroom algebra.

Driving hours used today. The cumulative driving hours since the end of the last qualifying 10-hour rest period (or qualifying sleeper split). Pulled from the ELD's current-shift driving counter. Decimal hours allowed — 7.5 means 7 hours 30 minutes.

On-duty hours used today. The cumulative on-duty hours since the same rest period. Includes driving plus pre-trip and post-trip inspection, fueling, loading and unloading, paperwork, and any other compensated work. Generally exceeds the driving hours figure by the time spent on non-driving tasks.

Driving hours since last 30-minute break. The driving-only counter that resets on any qualifying 30-minute non-driving interruption. Pulled from the ELD's break-cycle counter or computed by hand from the duty-status log.

On-duty hours over rolling 7-day window. Sum of on-duty hours over the most recent 7 consecutive days, for carriers electing the 60-hour cycle. Pulled from the ELD's cycle counter.

On-duty hours over rolling 8-day window. Sum of on-duty hours over the most recent 8 consecutive days, for carriers electing the 70-hour cycle. Pulled from the ELD's cycle counter. The carrier elects one cycle or the other; supplying both gives the calculator a defensive picture (effective weekly headroom is the smaller of the two).

Last 10-hour rest ended at (UTC epoch seconds). UTC epoch timestamp at which the most recent qualifying 10-hour rest (or sleeper split) ended. The calculator adds the required rest hours to this timestamp to produce the next-permissible-drive timestamp. UTC epoch seconds is a precise format that avoids time-zone ambiguity. Pass 0 to skip the timestamp calculation.

Sleeper-berth split election. One of none, 8/2, or 7/3. Determines the required rest hours used in the next-permissible-drive timestamp calculation.

Industry benchmarks and enforcement context

HOS compliance is the single most-enforced area of motor-carrier regulation, and the most heavily-weighted BASIC score in the FMCSA Compliance, Safety, Accountability (CSA) Safety Measurement System. A carrier above the FMCSA intervention threshold on the HOS-Compliance BASIC faces increased roadside inspection rates, targeted safety audits, and (for the worst-performing carriers) an Unsatisfactory safety rating that effectively shuts down operating authority.

Roadside inspection data from the FMCSA shows that HOS-related violations are consistently among the top 5 driver violation categories at roadside inspection — typically False Log (49 CFR § 395.8(e)), Hours-of-Service Violations (49 CFR § 395.3), and No Record-of-Duty-Status (49 CFR § 395.8(a)). The 2017 ELD mandate dramatically reduced the False Log category by automating the duty-status capture, but increased the HOS-Compliance category because the ELD now objectively reports every minute the driver was in motion.

OOIDA (Owner-Operator Independent Drivers Association) tracks HOS rule-making and has published guidance on the 2020 rule changes, including the 30-minute break flexibility, the short-haul exception expansion (150 air miles, 14-hour shift), the adverse-driving exception clarification, and the sleeper-berth split flexibility. Owner-operators leased to a carrier are subject to the carrier's CSA score — a violation by the leased-on driver feeds the carrier's BASIC scores, which is why responsible carriers monitor leased-on driver HOS records as carefully as employee-driver records.

The shipper-side liability under 49 CFR § 395.3(e) — civil penalties for shippers, receivers, brokers, and freight forwarders that knowingly require or allow a driver to violate HOS rules — has reshaped customer-facing scheduling practices in the last decade. Shippers that schedule appointment times incompatible with HOS limits, refuse to load promptly, or pressure drivers to exceed limits face direct enforcement exposure. The driver's response when faced with shipper pressure: log the actual duty status accurately, decline the unsafe operation, and document the request — the ELD record protects the driver against carrier or shipper pressure to falsify.

What this calculator does NOT model

Several material adjacencies are intentionally outside scope.

The 34-hour restart provision (49 CFR § 395.3(c)). The calculator reports the weekly cycle headroom but does not schedule the restart. The restart is the driver's planning decision based on when the additional cycle headroom is most valuable. A restart consumes 34 consecutive off-duty hours; for a high-mileage driver with adequate cycle headroom on the natural roll, the restart is not always worth the time-cost.

The adverse-driving conditions exception (49 CFR § 395.1(b)(1)). Adds up to 2 hours to the 11-hour drive limit and 14-hour window when unforeseen conditions arise. The driver must annotate the ELD record with a description of the adverse condition; the carrier must retain the annotation as part of the supporting documents file. The calculator does not model this exception because it requires real-time human judgment about whether conditions are foreseeable.

The short-haul exception (49 CFR § 395.1(e)). Drivers operating within a 150-air-mile radius of the work-reporting location who return within 14 hours are exempt from the ELD requirement and follow a simplified records-of-duty-status regime. The calculator targets full-ELD drivers; short-haul operators have a different recordkeeping flow that does not map cleanly to the four-limit framework.

Hazmat security-sensitive cargo (49 CFR Part 397). Additional attendance and routing rules that interact with HOS — for example, the driver of an unattended placarded vehicle must be either in attendance or have parked in a designated safe haven. The calculator does not model these adjacencies.

Passenger-carrying CMV (49 CFR § 395.5). Passenger drivers operate under a separate 10/15/60-70 framework. This calculator covers property-carrying CMV only.

State-specific intrastate variations. Many states adopt the federal HOS framework for intrastate operations but vary on limits, exceptions, and the short-haul radius. The calculator targets interstate operations under federal jurisdiction.

For HOS enforcement actions, CSA score interventions, accident defense, or DOT audit response specifically: this is a planning tool. The right next step is a motor-carrier compliance consultant (for routine compliance and audit preparation), a transportation-focused attorney (for enforcement actions, CSA intervention response, and accident defense), and the FMCSA Compliance Assistance Service Center (for rule-interpretation questions).

Statute and source list

The calculator is reviewed against the following authorities. Last reviewed 2026-05-16.

• 49 USC Chapter 311 — Commercial Motor Vehicle Safety. Federal statutory framework.
• 49 CFR Part 395 — Hours of Service of Drivers. The full HOS rulebook for property-carrying and passenger-carrying CMV drivers.
  • § 395.1(b)(1) — Adverse-driving conditions exception.
  • § 395.1(e) — Short-haul exception (150 air-mile radius, 14-hour shift).
  • § 395.1(g) — Sleeper-berth split provision (8/2 and 7/3 qualifying splits).
  • § 395.3(a)(2) — 14-hour on-duty window.
  • § 395.3(a)(3) — 11-hour driving limit.
  • § 395.3(a)(3)(ii) — 30-minute break after 8 driving hours.
  • § 395.3(b) — 60/70-hour 7/8-day weekly cycles.
  • § 395.3(c) — 34-hour restart provision.
  • § 395.3(e) — Shipper, receiver, broker, and freight forwarder liability for HOS violations.
  • § 395.5 — Passenger-carrying CMV (separate framework, not covered by this calculator).
  • § 395.8 — Record-of-duty-status (RODS) requirements.
• 49 CFR Part 395 Subpart B — Electronic Logging Devices. Technical specifications, registered device list, supporting documents, record retention (6 months).
• 49 CFR Part 397 — Hazmat security-sensitive cargo attendance and routing.
• FMCSA Hours-of-Service final rule (84 FR 44190, 2019) — Implemented changes to the 30-minute break, short-haul exception, adverse-driving exception, and sleeper-berth split.
• FMCSA Compliance, Safety, Accountability (CSA) program — Safety Measurement System (SMS) BASIC scoring; HOS-Compliance BASIC.
• 49 USC § 521 — Civil penalties for HOS violations.
• OOIDA — Owner-Operator Independent Drivers Association — HOS research, rule-change advocacy, member-facing compliance guidance.
• FMCSA Compliance Assistance Service Center — Rule-interpretation guidance, safety-audit preparation, DataQs challenge process.

These are planning references, not legal, tax, insurance, or financial advice. Consult a licensed professional in your jurisdiction before acting on a result from this calculator.