An hours of service calculator for US truck drivers
This HOS calculator reads a simple duty log — the times you changed between driving, on duty, off duty and sleeper berth — and shows how much driving time you have left under the US hours-of-service rules for property-carrying drivers: the 11-hour driving limit, the 14-hour window, the 30-minute break after 8 hours of driving, and the 60/70-hour weekly limit with a recap for tomorrow and the 34-hour restart.
It is a planning aid for drivers and dispatchers working out a trip — not an ELD, not a record of duty status and not legal advice. Your electronic logging device, your carrier’s policy and the regulations decide what is legal. Everything runs in your browser; the log is kept on this device only.
How to use the Hours of Service Calculator
- Enter the time you came on duty after at least 10 hours off, then add a row for each change of status.
- Set the current time (or press Now).
- Choose 70 hours / 8 days or 60 hours / 7 days, and tick adverse driving conditions if they apply.
- Enter your on-duty hours for the previous days and any 34-hour restart.
- Read the driving time available now, which limit binds first, and the hours you will have tomorrow.
Hours of Service Calculator features
Four limits at once
11-hour driving, 14-hour window, 8-hour driving before a break, and 60/70 hours — the smallest wins and is named.
Break detection
Any 30 consecutive minutes off duty, in the sleeper berth or on duty not driving resets the 8-hour clock.
Shift reset
10 or more consecutive hours off duty or in the sleeper berth starts a new 14-hour window, even across midnight.
Recap for tomorrow
Adds today to the previous days of the cycle and shows what is free tomorrow if you stop now.
Violation flags
Driving after 11 hours, after the 14th hour or 8 hours without a break is listed with the overrun.
The property-carrying HOS rules used here
Source: 49 CFR Part 395 as published in the eCFR (via Cornell LII), checked 19 October 2026.
| Rule | Limit | Regulation |
|---|---|---|
| Shift start | 10 consecutive hours off duty before driving | 395.3(a)(1) |
| 14-hour window | No driving after the 14th hour since coming on duty | 395.3(a)(2) |
| Driving limit | 11 hours of driving within the 14-hour window | 395.3(a)(3)(i) |
| 30-minute break | No driving after 8 hours of driving without a 30-minute interruption (off duty, sleeper berth or on duty not driving) | 395.3(a)(3)(ii) |
| Weekly limit | 60 hours on duty in 7 days, or 70 hours in 8 days if the carrier runs every day | 395.3(b) |
| 34-hour restart | A period of 34 or more consecutive hours off duty starts a new 7- or 8-day period | 395.3(c) |
| Adverse conditions | Up to 2 extra hours of driving and window to finish the run or reach safety | 395.1(b)(1) |
Worked example
A driver comes on duty at 06:00, drives 06:30–11:00, takes 30 minutes off, drives 11:30–15:00, loads for an hour and drives again from 16:00. At 18:00 they have driven 10 hours, so 1 hour of the 11-hour limit is left; the 14-hour window closes at 20:00; the hour of loading counted as a break, so 6 hours remain before another break is needed. With 54.5 hours on the previous seven days plus 11.5 today, 66 of 70 hours are used. The binding limit is the 11-hour rule: drive until 19:00. If they stop now, the 10 hours from seven days ago drop off and 14 hours are free tomorrow.
What this calculator does not cover
For trip costs see the truck cost per mile calculator and the fuel surcharge calculator.
- Sleeper-berth split periods (7/3 or 8/2), which pause the 14-hour window, are not modelled: a sleeper period shorter than 10 hours is treated like off-duty time.
- Short-haul exceptions (150 air-mile radius), agricultural, oilfield and other exemptions, and the passenger-carrying rules.
- Canadian or other national driving-time rules, and state intrastate rules. For the GB/EU rules (9 hours a day, a 45-minute break after 4.5 hours, 56 and 90 hours) use the drivers’ hours calculator.
- Personal conveyance and yard moves. Check these with your carrier.
Hours of Service Calculator FAQ
How do I calculate my hours of service?
Count driving time since your last 10 hours off (limit 11), time since you came on duty (limit 14), driving since your last 30-minute break (limit 8), and on-duty time over the last 7 or 8 days (limit 60 or 70). The smallest remainder is what you can drive. This calculator does it from your log.
What is an HOS recap?
A recap shows the hours you have used in the 60/70-hour cycle and how many come back each day as the oldest day drops off. Enter your previous days and the tool shows what is available tomorrow.
Does an on-duty stop count as the 30-minute break?
Yes. Since the 2020 changes, 30 consecutive minutes off duty, in the sleeper berth or on duty not driving all satisfy the break requirement.
Does a lunch break stop the 14-hour clock?
No. Off-duty time inside the window does not extend it; only a qualifying sleeper-berth split pauses it.
What resets the 70-hour clock?
A 34-hour restart: 34 or more consecutive hours off duty. Without one, hours come back as each old day leaves the 8-day window.
Can I use this as my log?
No. It is a planning aid only — not an ELD and not a record of duty status. Use your ELD for compliance.