This calculator subtracts the hours you’ve already used from the FMCSA’s 70-hour, 8-day on-duty limit, and adds back any hours that roll off the 8-day lookback window, so you can see how many on-duty hours remain available.
70 Hour 8 Day Recap Calculator
Hours available to drive under the FMCSA 70-hour/8-day rule, and hours "recaptured" as the oldest day rolls off the 8-day window.
What the 70-Hour/8-Day Recap Calculator Covers
Under the FMCSA’s 70-hour/8-day rule, a commercial driver may not drive after accumulating 70 hours on duty within any 8 consecutive days. This calculator covers 70-hour recap tracking, remaining available hours, and the “rolling” nature of the 8-day window, where hours from 8 days ago drop off and become available again each day.
Dispatchers and drivers use a recap calculation daily to plan routes without risking a hours-of-service violation, since the 70-hour limit is a rolling total rather than a fixed weekly reset.
How Available Hours Are Calculated
Formula
Available Hours Today = 70 − Hours Used in the Past 8 Days
Available Hours Tomorrow = 70 − Hours Used in the Past 8 Days + Hours Rolling Off Tomorrow
Where:
- Hours Used = total on-duty hours logged over the current rolling 8-day window
- Hours Rolling Off = on-duty hours from the oldest day in the window, which drop out of the count as the window advances
Worked Example
A driver has logged 58 hours over the past 8 days, and 6 of those hours fall on the day that will roll off the window tomorrow.
Available Today = 70 − 58 = 12 hours
Available Tomorrow = 70 − 58 + 6 = 18 hours
This driver has 12 hours available to drive today, and that availability grows to 18 hours tomorrow once the oldest day’s 6 hours roll off the lookback window.
Why the Rolling Window Trips People Up
Unlike a simple weekly reset, the 8-day window recalculates every single day, dropping the oldest day and adding the newest. That means available hours can increase day to day even without a 34-hour restart, simply because older high-hour days fall out of the count.
Frequently Asked Questions
Is this the same as a 34-hour restart?
No. A recap tracks the rolling 8-day window day by day, while a restart resets the clock entirely after 34 consecutive off-duty hours. Drivers can use either strategy, and some carriers use both depending on operational needs.
Do off-duty and sleeper-berth hours count toward the 70-hour limit?
No — only on-duty time (driving and on-duty-not-driving) counts toward the 70-hour total. This is not legal advice; always confirm current hours-of-service definitions with your carrier’s compliance guidance or the FMCSA.
What if I operate under a 60-hour/7-day rule instead?
Some carriers use the 60-hour/7-day cycle rather than 70-hour/8-day. Enter your actual on-duty totals and rolling limit accordingly, keeping in mind this calculator is set up around the 70-hour/8-day structure.
Why did my available hours go down even though I didn’t drive?
If a new day enters the 8-day window with more logged on-duty hours than the day that rolled off, your available hours can decrease even without additional driving that day.