About the Hours of Service Calculator
This hours of service (HOS) calculator applies the US Federal Motor Carrier Safety Administration limits for property-carrying commercial drivers in 49 CFR 395.3. Enter how long you have driven since your last 10-hour break, how long ago you came on duty, how much you have driven since your last 30-minute break and your on-duty total for the last 7 or 8 days. It shows how many hours you can still legally drive, which rule runs out first and the clock time your 14-hour window closes.
It is built for owner-operators, company drivers and dispatchers planning a trip or checking whether a load can be delivered today. The 11-hour driving limit, 14-hour window, 30-minute break after 8 hours of driving and the 60-hour/7-day or 70-hour/8-day cycle are all checked at once, and the optional adverse-driving-conditions exception adds up to two hours to the driving limit and window.
Rules reflect 49 CFR Part 395 as in force in 2026. The calculator does not model the sleeper-berth split, the 150 air-mile short-haul exception, passenger-carrying limits or state intrastate rules, and it is a planning aid — your ELD record is what counts at a roadside inspection.
With the default inputs, the driving time available now is 4.5 hours. Change any value above to recalculate instantly.
How to use the hours of service calculator
- 1Choose your carrier’s cycle: 70 hours/8 days or 60 hours/7 days.
- 2Enter hours driven since your last 10-hour break and hours since you came on duty.
- 3Enter driving hours since your last 30-minute break.
- 4Enter your on-duty total over the rolling 7 or 8 days, including today.
- 5Read the driving time available, the binding rule and when your window closes.
Formula and method
Under 49 CFR 395.3, a property-carrying driver may drive up to 11 hours after 10 consecutive hours off duty, may not drive after the 14th consecutive hour since coming on duty, must take a 30-consecutive-minute interruption once 8 hours of driving have accumulated, and may not drive after 60 on-duty hours in 7 days or 70 in 8 days (the cycle can be reset by 34 consecutive hours off).
The calculator works out what remains on each clock and takes the smallest. Because the 14-hour window keeps running during breaks, if you still need a 30-minute break before you would hit another limit, half an hour is subtracted from the window time available for driving. With the adverse-conditions exception, the 11 and 14 become 13 and 16.
- 11 h
- Maximum driving after 10 consecutive hours off duty
- 14 h
- Driving window measured from coming on duty
- 8 h
- Cumulative driving allowed before a 30-minute interruption
- 60/70 h
- On-duty limit over 7 or 8 consecutive days
Worked examples
Mid-shift check: 6.5 h driven, 8 h on duty
You have 11 − 6.5 = 4.5 hours of driving left and 14 − 8 = 6 hours left in the window. You must take a 30-minute break after 3.5 more hours of driving, which still leaves 5.5 hours of window, so the 11-hour limit binds at 4.5 hours.
Long on-duty day — the 14-hour window binds
Only 5 hours of driving are used, but after 11 hours on duty (loading, waiting, fueling) just 3 hours of the 14-hour window remain. No break is needed within those 3 hours, so you can drive 3 hours until 19:30.
End of the week on a 70-hour cycle
With 67.5 on-duty hours in the last 8 days only 2.5 hours remain in the 70-hour cycle, even though the daily clocks have plenty left. A 34-hour restart would reset the cycle.
Break needed before the window closes
Four hours remain in the window and four on the 11-hour limit, but you must stop for 30 minutes after 1 more hour of driving. The break uses half an hour of the window, leaving 3.5 hours of driving.
Break due just as the window is closing
Only 1 hour of the 14-hour window remains and the 8-hour break clock runs out after 30 more minutes of driving. Taking the 30-minute break would use up the rest of the window, so you can drive just 0.5 hours today.
Frequently asked questions
What is the 11-hour driving rule?+
A property-carrying driver may drive a maximum of 11 hours after taking 10 consecutive hours off duty. Once 11 hours of driving are logged, no more driving is allowed until another 10 consecutive hours off duty (or a qualifying sleeper-berth split).
How does the 14-hour rule work?+
The 14-hour window starts when you begin any work after 10 hours off and runs continuously — lunch, fuel stops and off-duty breaks do not pause it. You may keep doing on-duty work after the 14th hour, but you may not drive.
When do I need a 30-minute break?+
You must take at least 30 consecutive minutes away from driving once you have accumulated 8 hours of driving time without such an interruption. Since 2020 the break can be off duty, in the sleeper berth or on-duty not driving, such as fueling or loading.
What is the 70-hour rule and how do I reset it?+
If your carrier operates every day, you may not drive after 70 on-duty hours in any 8 consecutive days (60 hours in 7 days otherwise). Hours roll off as old days drop out, or you can reset to zero with 34 or more consecutive hours off duty.
Do these rules apply to bus drivers?+
No. Passenger-carrying drivers follow 49 CFR 395.5: up to 10 hours of driving after 8 consecutive hours off, and no driving after 15 on-duty hours, with the same 60/70-hour weekly limits. This calculator covers property carriers only.
What counts as adverse driving conditions?+
Snow, fog, ice or unusual traffic that the driver or dispatcher did not know about when the trip was dispatched. The exception allows up to 2 additional hours of driving and window time to finish the run or reach a safe place; it does not cover known weather or routine congestion.
Results are general estimates and not legal advice. Laws vary by jurisdiction — consult a qualified attorney.