HOS Hours Remaining Calculator

Understanding Hours of Service (HOS) Rules

Hours of Service regulations are federal rules that limit how long commercial motor vehicle (CMV) drivers can operate before mandatory rest periods. Codified in § Part 395 ¹, these rules exist to prevent fatigue-related accidents and are enforced by the Federal Motor Carrier Safety Administration (FMCSA).

For most truck drivers operating property-carrying vehicles, four main rules govern your driving time. Understanding how these rules interact is crucial for maximizing your productivity while staying compliant.

The 11-Hour Driving Limit § 395.3(a)(3)(i) ¹

You may drive a maximum of 11 hours after 10 consecutive hours off duty. This is the most straightforward HOS rule but often not the most restrictive. Many drivers find their 14-hour window expires before they use all 11 driving hours.

Example: A driver starts at 6:00 AM after a full 10-hour break. They can drive until they accumulate 11 hours of driving time. If they drive 5 hours, stop for a 2-hour delivery, and drive 4 more hours, they have used 9 of their 11 driving hours with 2 still available.

The key to maximizing your 11 hours is minimizing non-driving on-duty time. Every hour spent on pre-trip inspections, fueling, paperwork, or waiting at shippers is time that cannot be used for driving within your 14-hour window.

The 14-Hour On-Duty Window § 395.3(a)(2) ¹

Once you come on duty following your 10-hour break, you have a 14-hour window to complete all your driving. This clock runs continuously and cannot be stopped for breaks, meals, or other off-duty time.

Example: Your shift starts at 6:00 AM. Your 14-hour window closes at 8:00 PM regardless of how much driving you actually did. If you spend 4 hours at a shipper waiting to be loaded, you have effectively lost 4 hours of potential driving time. You still have all 11 driving hours available, but only 10 hours of window left to use them.

This is often the rule that catches drivers off guard. Strategic tip: When possible, schedule deliveries and pickups that minimize wait times. Some drivers start their day with driving and save paperwork and other on-duty tasks for when their driving hours are exhausted.

The 60/70-Hour Cycle Limit § 395.3(b) ¹

Drivers cannot drive after 60 hours on duty in 7 consecutive days or 70 hours on duty in 8 consecutive days. Most carriers operate on the 70-hour/8-day cycle, which provides more flexibility for consistent schedules.

This is a rolling limit that recalculates daily. Each day, the oldest day's hours drop off your total. For example, on day 9 of your cycle, day 1's hours are no longer counted.

Example: You worked 10 hours/day for 7 days = 70 hours total. On day 9, day 1's 10 hours drop off, so your new total is 60 hours with 10 hours available. This is why our calculator offers day-by-day cycle tracking — knowing which day's hours expire next is critical for planning.

Alternatively, a 34-hour restart resets your cycle hours to zero § 395.3(c) ¹. The restart must include two consecutive periods from 1:00 AM to 5:00 AM. Many drivers use weekends for restarts.

The 30-Minute Break Requirement § 395.3(a)(3)(ii) ¹

Drivers must take a 30-minute break after 8 cumulative hours of driving without at least a 30-minute interruption. The break can be off-duty or on-duty not driving (such as waiting at a shipper).

Example: You drive 4 hours, spend 45 minutes at a fuel stop (which satisfies the break requirement), then drive 4 more hours. Since the 45-minute stop reset the break clock, you have 8 more driving hours before the next break is needed.

This rule was modified in 2020 to count only driving time, not total on-duty time. This gives drivers more flexibility. If you drive 4 hours, spend 2 hours at a shipper, then drive 4 more hours, you have not triggered the break requirement because only 8 hours of driving occurred (exactly at the limit).

How the Rules Interact

The challenge of HOS compliance is that all four rules apply simultaneously. You might have 8 hours of driving remaining on your 11-hour limit, but only 6 hours left on your 14-hour window. Your most restrictive limit determines how much driving you can actually do — which is exactly what our calculator highlights at the top of the results.

Similarly, you might have plenty of daily hours but be approaching your 70-hour weekly limit. Smart trip planning requires awareness of all four limits and which one will run out first. Our “Can I Make This Load?” feature helps you answer this question instantly.

Common HOS Misconceptions

Myth: Taking a break pauses your 14-hour clock. False. The 14-hour window runs continuously from when you start your duty period until you take a 10-hour break. Off-duty time (except the 10-hour break) does not stop this clock.

Myth: Sleeper berth time counts the same as off-duty. Partially true. Sleeper berth time can satisfy break requirements, but the split sleeper berth provision § 395.1(g) ¹ has specific rules about how time is divided. A 7/3 or 8/2 split requires both periods to be either off-duty or sleeper berth time.

Myth: Personal conveyance is unlimited. False. Personal conveyance (driving the CMV for personal reasons while off-duty) is allowed but must be reasonable and cannot be used to extend your driving day. Using personal conveyance to reach a better parking spot after exhausting hours is acceptable; using it to make progress toward your destination is not.

Specialty Operations & Exceptions

The rules above apply to standard property-carrying CMV operations. Several exceptions and modified rules exist:

• Short-haul exception § 395.1(e)(1) ¹: Drivers who operate within 150 air-miles and return to their reporting location within 14 hours may use time cards instead of ELDs.
• Adverse driving conditions § 395.1(b)(1) ¹: Allows up to 2 additional hours of driving (13 total) for unexpected weather, traffic, or road conditions. Does not extend the 14-hour window.
• Hazmat operations: Same HOS rules apply, but violations carry higher CSA severity weights and penalties.
• Passenger-carrying vehicles: Subject to different limits under § 395.5 ¹ (10 hours driving, 15-hour window).
• Cross-border operations: Drivers crossing between the US and Canada or Mexico must comply with the rules of the country they are currently operating in.