Truck Driver Hours Calculator
Used hours to drive, duty, and cycle time left.
What it does
Hours-of-service math decides whether the wheels keep turning legally. Three clocks run at once: 11 driving, 14 duty, 70 per eight days. Whichever hits zero parks the truck.
The tool above subtracts used hours from each limit and reports the three remainders with a plain status. Feed it ELD numbers mid-shift; it flags over-limit lines at zero instead of hiding them.
FMCSA publishes these property-carrier limits with the 30-minute break and sleeper-berth rules, and owner-operator groups teach the same 11/14/70 trio in plain terms. Short-haul, passenger, and specialty rules bend the edges, but the trio rules most highway days.
Check early and often. A driver with 4.5 drive hours but 1 duty hour left parks in one hour regardless. Plan fuel, breaks, and parking against the smallest remainder, not the biggest.
How to use
- Enter driving hours used this shift.
- Enter on-duty hours used this shift.
- Enter 8-day cycle hours used.
- Read the three remainders.
- Read the compliance status.
- Rest before any remainder hits zero.
Formula
- drive used
- Driving hours already logged this shift.
- duty used
- On-duty hours already logged this shift.
- cycle used
- On-duty hours in the last 8 days.
Property-carrying interstate limits with whole or decimal hours. Used hours come from the ELD or log grid. Any negative remainder reads 0 with an over-limit status; passenger, short-haul, oilfield, and Alaska rules differ.
Worked example
Example: 6.5 / 9 / 32 used
Mid-shift property driver, 6.5 driving, 9 duty, 32 cycle hours used.
- Drove 6.5 hr, on duty 9 hr, cycle 32 hr.
- Drive left: 11 - 6.5 = 4.5 hr.
- Duty left: 14 - 9 = 5 hr.
- Cycle left: 70 - 32 = 38 hr.
- Status reads Compliant, keep logging.
Reference table
| Clock | Limit | Resets |
|---|---|---|
| Driving | 11 hr | After 10 off |
| Duty window | 14 hr | After 10 off |
| Cycle | 70 hr / 8 days | 34-hr restart |
| Break | 30 min by 8 hr driving | Off duty |
| Sleeper split | 7/3 or 8/2 pairs | Strict pairing rules |
Limits
- Property interstate defaults. Passenger and specialty rules differ.
- No sleeper-split or adverse-condition math.
- ELD is the record; this is a planning check.
- State intrastate variants vary.
Common mistakes
- Watching drive hours while duty expires.
- Forgetting the 30-minute break.
- Ignoring the 8-day cycle until day 7.
- Mixing passenger limits into freight math.
- Trusting memory over the ELD.
Try it yourself
Quick checks. Answers sit tucked under each question.
Left after 8 driving, 12 duty, 55 cycle?
Drive left 11 - 8 = 3 hr. Duty left 14 - 12 = 2 hr. Cycle left 70 - 55 = 15 hr.
Left after 11 driving, 13.5 duty, 69 cycle?
Drive left 11 - 11 = 0 hr. Duty left 14 - 13.5 = 0.5 hr. Cycle left 70 - 69 = 1 hr. Park when the half hour expires.
Questions
What are the big HOS numbers?
11 hours driving inside a 14-hour duty window, then 10 off, inside 70 hours per 8 days for property carriers. Short-haul and adverse rules bend pieces; the big three numbers rule most days.
What is the 14-hour window?
On-duty time after coming on duty, including fueling, loading, and inspections. Off-duty pauses do not stretch it (except valid sleeper splits). When it ends, driving ends too.
What is the 70-hour cycle?
70 hours on duty in 8 days for most carriers (60 in 7 for some). The 34-hour restart resets it. Track it and the daily pair together.
Is there a break rule too?
Yes: 30 minutes off duty before 8 hours of driving time pass. Short-haul exceptions differ. Plan the break before the clock forces it.
Do sleeper splits change the math?
Sleeper berth splits (like 8/2 or 7/3) pause and reshape the windows under strict pairing rules. This page covers single-shift math; split math needs the berth entries.
What happens for going over?
ELD flags, roadside violations, fines, and out-of-service orders. Carriers audit logs against fuel and GPS, so paper optimism dies fast.