70 Hours / 8 Days (Interstate/OTR)
60 Hours / 7 Days (Intrastate/Local)
Excluding today's hours
Time elapsed since coming on duty
Remaining on 11-Hour Drive Clock:0.00 hrs
Remaining on 14-Hour Shift Clock:0.00 hrs
Remaining on Cycle (70hr):0.00 hrs
MAXIMUM DRIVING TIME AVAILABLE:0.00 hrs
function calculateHOS() {
// Inputs
var cycleType = parseFloat(document.getElementById("cycleType").value);
var prevCycleHours = parseFloat(document.getElementById("prevCycleHours").value);
var hoursSinceStart = parseFloat(document.getElementById("hoursSinceStart").value);
var hoursOnDutyToday = parseFloat(document.getElementById("hoursOnDutyToday").value);
var hoursDrivingToday = parseFloat(document.getElementById("hoursDrivingToday").value);
// Validation
if (isNaN(prevCycleHours)) prevCycleHours = 0;
if (isNaN(hoursSinceStart)) hoursSinceStart = 0;
if (isNaN(hoursOnDutyToday)) hoursOnDutyToday = 0;
if (isNaN(hoursDrivingToday)) hoursDrivingToday = 0;
// Constants
var driveLimit = 11.0;
var shiftLimit = 14.0;
// 1. Calculate Remaining Drive Time (11 Hour Rule)
var remainingDrive = driveLimit – hoursDrivingToday;
// 2. Calculate Remaining Shift Time (14 Hour Rule)
// Note: You cannot drive after the 14th hour since coming on duty.
var remainingShift = shiftLimit – hoursSinceStart;
// 3. Calculate Remaining Cycle Time (60/70 Hour Rule)
var totalCycleUsed = prevCycleHours + hoursOnDutyToday;
var remainingCycle = cycleType – totalCycleUsed;
// Ensure no negative values for display logic
var displayDrive = remainingDrive > 0 ? remainingDrive : 0;
var displayShift = remainingShift > 0 ? remainingShift : 0;
var displayCycle = remainingCycle > 0 ? remainingCycle : 0;
// 4. Determine Actual Available Driving Hours
// The available driving time is the lowest number among the three restrictions.
var availableToDrive = Math.min(remainingDrive, remainingShift, remainingCycle);
if (availableToDrive < 0) availableToDrive = 0;
// Update DOM
document.getElementById("cycleLabel").innerText = cycleType;
document.getElementById("res11").innerText = remainingDrive.toFixed(2) + " hrs";
document.getElementById("res14").innerText = remainingShift.toFixed(2) + " hrs";
document.getElementById("resCycle").innerText = remainingCycle.toFixed(2) + " hrs";
document.getElementById("resFinal").innerText = availableToDrive.toFixed(2) + " hrs";
// Status Message and Color Logic
var statusMsg = document.getElementById("statusMessage");
var resultsBox = document.getElementById("hosResults");
resultsBox.style.display = "block";
if (remainingDrive < 0 || remainingShift < 0 || remainingCycle < 0) {
statusMsg.innerHTML = "VIOLATION You are currently in violation of HOS rules.";
} else if (availableToDrive === 0) {
statusMsg.innerHTML = "STOP DRIVING You have no driving hours remaining.";
} else {
statusMsg.innerHTML = "COMPLIANT You are good to drive.";
}
// Visual cues for negative numbers in individual rows
document.getElementById("res11").style.color = remainingDrive < 0 ? "#dc3545" : "#212529";
document.getElementById("res14").style.color = remainingShift < 0 ? "#dc3545" : "#212529";
document.getElementById("resCycle").style.color = remainingCycle < 0 ? "#dc3545" : "#212529";
}
Understanding DOT Hours of Service (HOS)
For commercial truck drivers in the United States, adhering to the Hours of Service (HOS) regulations mandated by the Federal Motor Carrier Safety Administration (FMCSA) is critical for safety and compliance. These rules are designed to prevent accidents caused by driver fatigue. This calculator helps drivers and fleet managers quickly determine remaining driving time based on the three primary "clocks": the 11-hour rule, the 14-hour rule, and the 60/70-hour cycle limit.
The 11-Hour Driving Limit
This rule states that a driver may drive a maximum of 11 hours after 10 consecutive hours off duty. Once you have driven 11 hours, you must take 10 consecutive hours off duty before you can drive again. This calculator subtracts your driving time today from the 11-hour limit to show your remaining allowance.
The 14-Hour Duty Window
The 14-hour rule is often the most confusing for new drivers. It dictates that you may not drive beyond the 14th consecutive hour after coming on duty, following 10 consecutive hours off duty. Unlike the 11-hour clock, the 14-hour clock does not stop for breaks, naps, or waiting time (unless using the Split Sleeper Berth provision properly). It is a continuous countdown from the moment you start your shift.
The 60/70-Hour Cycle Limit
This limit prevents cumulative fatigue over several days. It restricts drivers from driving after having been on duty for:
60 hours in 7 consecutive days (for carriers that do not operate every day of the week).
70 hours in 8 consecutive days (for carriers that operate every day of the week).
This calculator sums your hours from the previous days in your cycle plus your hours today to determine how much of your weekly "bank" is remaining.
How to Use This Calculator
To get an accurate result, you need your current logbook status:
Select Cycle: Choose between the 70/8 rule (Interstate/OTR) or 60/7 rule.
Previous Cycle Hours: Input the total On-Duty hours worked in the last 7 days (for 70/8) or 6 days (for 60/7), excluding today.
Hours Since Shift Start: Enter how many hours have passed since you first punched in today. This calculates your 14-hour window.
Hours On-Duty Today: Enter total hours worked today (Driving + On-Duty Not Driving).
Hours Driving Today: Enter specifically how many hours you have spent driving today.
The result will show the minimum time available across all three rules, ensuring you stay compliant with whichever limit you are approaching first.