Hours of Service Calculator
Track your 11/14/70-hour HOS clocks.
Educational estimate only. Always confirm against your ELD's official HOS clocks before driving.
Get More Out of the HOS Calculator
Three Clocks Run at Once
The 11-hour driving limit, the 14-hour on-duty window, and the 60 or 70-hour cycle all tick simultaneously, and whichever runs out first is the one that stops you, regardless of the other two.
Plan the Week, Not Just Today
Cycle hours accumulate across 7 or 8 days depending on which rule your carrier uses, so a heavy prior week can force a shorter driving day today even with plenty of hours left on the daily clocks.
This Is a Planning Tool, Not Your Official Log
This calculator gives an educational estimate to plan around. Your ELD is the legal record of your hours, and it should always be the final word before you get behind the wheel.
HOS Calculator: Formula, Benchmarks, and a Worked Example
Running out of driving hours mid-route or discovering a 34-hour restart is required costs real money and real time, and both are easier to plan around than to react to. This calculator estimates your remaining 11-hour driving window, 14-hour on-duty window, and 60 or 70-hour cycle balance from the hours you've already logged, so you can plan the rest of the day and the coming week before your ELD forces the decision for you.
What This Calculator Actually Tracks
Federal hours-of-service rules for property-carrying drivers run three clocks at once: an 11-hour limit on actual driving time, a 14-hour window from when you first go on duty within which that driving must happen, and a rolling 60-hour (7-day) or 70-hour (8-day) cycle limit on total on-duty time. This calculator estimates how much room you have left on each of the three based on what you enter for today and the prior week.
The Formula Behind This Calculator
Driving hours remaining today is 11 minus the hours you've already driven today, floored at zero. On-duty hours remaining today is 14 minus the hours you've already been on duty today, also floored at zero. Cycle hours remaining is your chosen cycle limit, either 60 or 70, minus your on-duty hours from the last 7 days (or 8, excluding today) minus today's on-duty hours, floored at zero.
If cycle hours remaining reaches zero, the calculator flags that a 34-hour restart is needed to reset the cycle clock back to full before you can log any more on-duty time under that cycle.
Realistic Industry Benchmarks
Most company policies and dispatch planning build in a buffer below the hard federal limits, commonly stopping drivers around 10 hours of driving or 13 hours on duty rather than running the clock all the way to 11 or 14, to leave margin for traffic, weather, or a delayed appointment. A driver running close to the weekly cycle limit for several days in a row is a common early warning sign that a 34-hour restart is coming up soon.
A Worked Example
Using this calculator's defaults: 4 hours driven today, 5 hours on duty today, 40 on-duty hours logged over the last 7 days excluding today, and the 70-hour, 8-day cycle selected. Driving hours remaining today is 11 minus 4, or 7 hours. On-duty hours remaining today is 14 minus 5, or 9 hours.
Cycle hours remaining is 70 minus 40 minus 5, or 25 hours left in the cycle. Since 25 is well above zero, no 34-hour restart is needed yet, and the driver has 7 more hours of driving available today, limited by whichever clock, driving, on-duty, or cycle, runs out first.
Why Tracking All Three Clocks Matters
It's easy to watch only the driving clock and get caught off guard by the 14-hour or cycle limit instead, since either can force a stop well before 11 hours of driving are used. Planning around whichever clock is tightest on a given day, rather than just the driving hours, avoids getting stuck short of a planned stop or delivery appointment.
Common Mistakes With This Number
The most common mistake is tracking only the 11-hour driving limit and ignoring the 14-hour on-duty window, which can end the driving day earlier than expected if a lot of time was spent on duty but not driving, like at a shipper or fueling. The second is losing track of cycle hours across a busy week and getting surprised by a forced 34-hour restart right when a load needs to move.
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What Owner-Operators Say
“I used to just watch my driving hours and got caught by the 14-hour window more than once. Now I check all three clocks before I plan a day.”
“Knowing my cycle hours ahead of time lets me plan a restart around my schedule instead of getting forced into one mid-week.”