Calculator 07 / Hours of Service
Hours of Service Calculator
Two clocks run at once: the 11-hour driving limit and the 14-hour on-duty window. Whichever runs out first is the one that stops you. A quick estimate of remaining drive time under the 11-hour driving limit and 14-hour on-duty window.
How this calculator works
The 14-hour on-duty window starts ticking the moment you come on duty and doesn't pause for breaks, fuel stops, or loading/unloading — only 10 consecutive hours off duty resets it. The 11-hour driving limit is separate and only counts actual driving time within that window. Whichever limit you hit first is what actually stops you — this calculator shows both and takes the smaller (more restrictive) one as your real remaining drive time.
Worked example: which limit is actually binding
On duty at 06:00, the clock now reading 15:00, 6.5 hours driven, 30-minute break already taken:
- Elapsed on duty = 15:00 − 06:00 = 9.00 hr
- 14-hour window left = 14 − 9.00 = 5.00 hr
- 11-hour driving left = 11 − 6.50 = 4.50 hr
- The smaller of the two governs = 4.50 hr, on the 11-hour limit
Change one thing — 8.5 hours driven with the break not taken — and the answer becomes 0.00 hr, binding on the 30-minute break. The 14-hour window still shows 5.00 hours and the driving limit still shows 2.50, but neither is available: past 8 cumulative hours of driving without a qualifying interruption, driving is not permitted at all until the break is taken.
The property-carrying limits this models
These are the federal limits for property-carrying drivers in 49 CFR 395.3. The calculator models the first three rows and nothing else. Everything below them is real and still applies to you — it is simply not something this page can see.
| Limit | Value | Starts / resets on | Modelled here |
|---|---|---|---|
| Driving limit | 11 hr | 10 consecutive hours off duty | Yes |
| On-duty window | 14 hr | Coming on duty; runs on the clock and does not pause | Yes |
| Break requirement | 30 min | After 8 cumulative hours of driving time | Yes, as a checkbox |
| Off-duty requirement | 10 hr | Consecutive, before the next 11/14 can begin | No |
| Weekly limit | 60 hr / 7 days | Rolling; carriers not operating every day of the week | No |
| Weekly limit | 70 hr / 8 days | Rolling; carriers operating every day of the week | No |
| Restart | 34 hr | Optional, consecutive off-duty, resets the weekly total | No |
The 14-hour window is a clock, not a budget. It runs continuously from the moment you come on duty, and breaks, loading, fuelling and waiting all consume it without earning anything back. Only 10 consecutive hours off duty resets it. That is why the calculator asks for a start time and the current time rather than for hours worked.
The 30-minute break, precisely
This is the rule most often misremembered, and the 2020 revision changed it in two ways that matter. It is triggered by <em>driving</em> time, not on-duty time, and it can be satisfied without going off duty.
| Question | Answer |
|---|---|
| What triggers it? | 8 cumulative hours of driving time since the last qualifying interruption |
| How long? | At least 30 consecutive minutes |
| What counts? | Any 30 consecutive minutes not driving — off duty, sleeper berth, or on duty not driving |
| Does it pause the 14-hour window? | No. The window keeps running through it |
| What happens if you skip it? | Driving is prohibited until it is taken — this is not a recommendation |
Because on-duty-not-driving time now qualifies, time spent at a dock, on a pre-trip inspection or fuelling can satisfy the break — provided it is 30 consecutive minutes and it is logged that way. The checkbox on this page is a statement about your log, not a substitute for it.
Exceptions this calculator cannot apply
Each of these legitimately changes the numbers above, and none of them can be inferred from a start time and an odometer. If any applies to you, the figure on this page is the wrong figure.
| Provision | Reference | Effect |
|---|---|---|
| Short-haul exception | 395.1(e)(1) | Within 150 air-miles and a 14-hour duty period, relieves the record-of-duty-status requirement |
| Adverse driving conditions | 395.1(b)(1) | Extends both the driving limit and the 14-hour window by up to 2 hours |
| Sleeper berth split | 395.1(g) | 8/2 or 7/3 pairing; neither period counts against the 14-hour window |
| Personal conveyance | Interpretation to 395.8 | Off-duty movement, unladen and not for the carrier's benefit |
| Passenger-carrying drivers | 395.5 | Different regime entirely — 10 hours driving, 15-hour window, 8 hours off |
The passenger-carrying row is the one to watch. If you drive a bus or motorcoach, none of the numbers this calculator produces apply to you — the limits are 10, 15 and 8, not 11, 14 and 10. There is no setting on this page for that, deliberately: a calculator that quietly answers the wrong regulation is worse than one that says it does not cover you.
Why your ELD is the record and this is not
- The ELD is the legally required record. Under 49 CFR 395.8 and the ELD rule, your device's log is what an officer inspects and what an audit examines. Nothing typed into a web page has any standing.
- It knows your duty-status history; this page does not. The 60/70-hour totals, your last 34-hour restart, sleeper-berth pairings and yesterday's off-duty period are all in the ELD and none of them are inputs here.
- Your carrier's policy can be stricter than the regulation, and where it is, it governs your employment even though the federal rule would allow more.
- Canada and Mexico have their own rules. Cross-border operation is governed by the rules of the jurisdiction you are in, and Canadian hours-of-service limits differ from the US ones throughout.
- Rules change. The break and short-haul provisions above were revised in 2020. Check the current text of Part 395 rather than trusting a figure you memorised, or one you read here.
Where this goes wrong
- Entering driving time as on-duty time. "Hours driven" means time in the driving status. Loading, inspecting and waiting are on duty but not driving — they eat the 14-hour window without touching the 11-hour limit.
- Assuming the bigger number is the answer. The binding limit is whichever runs out first, and it changes during the day. The calculator names which one it is for exactly this reason.
- Expecting a break to buy back window time. It never does. Ten consecutive hours off duty is the only thing that resets the 14.
- Reading a comfortable number and stopping there. This page cannot see your 60/70-hour total, and running out of weekly hours with plenty of daily hours left is one of the most common ways drivers are put out of service.
- Using it in a bus or motorcoach. Passenger-carrying limits are different numbers under a different section.
- Treating it as a defence. It is a planning aid. If the figure here and your ELD disagree, your ELD is right and this page is wrong.
Where these numbers come from
Hours of service is enforced law, not guidance, and this tool is an estimate of it. The regulation itself is the only thing an officer at a roadside inspection is reading from.
- 49 CFR Part 395 — Hours of Service of Drivers — The regulation in full: the 11-hour driving limit, the 14-hour window, the 30-minute break, and every exception to them.
- 49 CFR Part 392 — Driving of Commercial Motor Vehicles — Includes the ill-or-fatigued-driver rule, which overrides any hours you have left on paper.
- 49 CFR Part 396 — Inspection, Repair and Maintenance — Where on-duty-not-driving time for inspections and repairs comes from.
Why doesn't this cover the 60/70-hour rule?
That limit depends on your total on-duty hours across the trailing 7 or 8 days (and whether you've taken a 34-hour restart), which requires tracking a rolling log this simple calculator doesn't have access to. Your ELD tracks this automatically.
What if my current time is before my start time?
The calculator assumes you're within the same on-duty period and handles times that cross midnight correctly — just make sure both times reflect today's actual shift.
Full compliance guide
This calculator models the 11-hour and 14-hour limits and the 30-minute break checkbox. For the 60/70-hour weekly limits, sleeper berth splits, and common violations it does not cover, see the DOT Hours-of-Service compliance guide.
Estimates only. This is not a substitute for your ELD or a review of the current FMCSA Hours of Service regulations. When in doubt, stop driving and consult your carrier's compliance team.