Less-than-Truckload (LTL) shipping involves transporting smaller shipments from multiple customers on a single truck. To determine the cost of these shipments, carriers use a standardized system of freight classes. There are 18 different freight classes, ranging from Class 50 (lowest cost) to Class 400 (highest cost), and sometimes even higher for exceptionally valuable or difficult-to-handle goods.
The freight class of a shipment is not determined by its weight alone. Instead, it's a complex rating system based on four key factors:
Density: This is the most significant factor, measuring how much space a shipment occupies relative to its weight. Denser items generally have lower freight classes.
Handling: This considers any special handling requirements, such as fragility, hazardous materials, or specific loading/unloading needs.
Stowability: This relates to how easily an item can be stowed with other freight. Items that are difficult to stack, oversized, or incompatible with other goods will have a higher stowability factor.
Liability/Value: This considers the potential risk to the carrier, including the value of the goods and the likelihood of damage or theft. High-value or easily damaged items typically have higher classes.
How the Freight Class is Calculated
While the official freight class is assigned by the National Motor Freight Traffic Association (NMFTA) and published in the NMFC (National Motor Freight Classification), this calculator provides an estimated freight class based on common industry practices and a simplified model.
The calculation typically involves comparing the shipment's density against predefined thresholds. Then, factors for handling, stowability, and exposure (or liability/value, approximated here by Value per Pound) are used to adjust the class up or down.
Our calculator uses the following logic:
Determine Base Class by Density: The shipment's weight per cubic foot is compared against a set of density thresholds. Each range of density corresponds to a base freight class. For example, higher density (more weight in a given volume) results in a lower base class.
Density thresholds are often standard but can be customized. Common thresholds (in lbs/ft³) might be: 2, 4, 6, 8, 10, 12, 15, 18, 20, 22.5, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 120, 150, 180, 200, 250, 300, 350, 400, 450, 500+.
These density ranges are mapped to base classes (e.g., Class 50, 55, 60, 65, 70, 77.5, 85, 92.5, 100, etc.).
Adjust Class based on Other Factors:
Handling: Hazardous or fragile items increase the class.
Stowability: Items that are difficult to stack or stow increase the class.
Exposure: Temperature-sensitive or items requiring special environmental conditions increase the class.
Value per Pound: Higher value per pound generally leads to a higher class, as it represents increased risk for the carrier.
This calculator simplifies these adjustments by adding predefined increments to the base class based on the selections for handling, stowability, exposure, and value. The specific increments can vary between carriers, but this tool provides a representative estimation.
Use Cases for this Calculator
This LTL Freight Class Calculator is valuable for:
Shippers: To get a preliminary estimate of their freight class before requesting quotes from carriers. This helps in understanding potential shipping costs and in preparing accurate shipping information.
Logistics Managers: To optimize shipping strategies and ensure correct classification for compliance and cost efficiency.
Small Businesses: To demystify the LTL shipping process and gain confidence in communicating shipment details to carriers.
New Entrants to Shipping: To learn about the factors that influence freight costs in the LTL industry.
Disclaimer: This calculator provides an estimated freight class for informational purposes only. It does not replace the official NMFC classification. Always confirm the final freight class with your chosen LTL carrier.
function calculateFreightClass() {
var weightPerCubicFoot = parseFloat(document.getElementById("weightPerCubicFoot").value);
var densityThresholdsStr = document.getElementById("densityThresholds").value;
var valuePerPound = parseFloat(document.getElementById("valuePerPound").value);
var handlingFactor = parseFloat(document.getElementById("handlingFactor").value);
var stowabilityFactor = parseFloat(document.getElementById("stowabilityFactor").value);
var exposureFactor = parseFloat(document.getElementById("exposureFactor").value);
var resultDiv = document.getElementById("result");
// Clear previous results and styling
resultDiv.innerHTML = "Your calculated freight class will appear here.";
resultDiv.classList.remove("success");
// — Input Validation —
if (isNaN(weightPerCubicFoot) || weightPerCubicFoot <= 0) {
resultDiv.innerHTML = "Please enter a valid weight per cubic foot.";
return;
}
if (densityThresholdsStr === "") {
resultDiv.innerHTML = "Please select density thresholds.";
return;
}
if (isNaN(valuePerPound) || valuePerPound < 0) { // Value can be 0
resultDiv.innerHTML = "Please enter a valid value per pound (can be 0).";
return;
}
if (isNaN(handlingFactor) || isNaN(stowabilityFactor) || isNaN(exposureFactor)) {
resultDiv.innerHTML = "Please select valid handling, stowability, and exposure factors.";
return;
}
// — Density Thresholds and Base Class Mapping —
// This is a simplified mapping. Real NMFC is more complex.
// We'll use common LTL classes: 50, 55, 60, 65, 70, 77.5, 85, 92.5, 100, 110, 125, 150, 175, 200, 250, 300, 350, 400.
// Example thresholds and corresponding base classes:
// Density (lbs/ft³) | Class
// < 2 | 400
// 2 – < 4 | 350
// 4 – < 6 | 300
// 6 – < 8 | 250
// 8 – < 10 | 200
// 10 – < 12 | 175
// 12 – < 15 | 150
// 15 – < 18 | 125
// 18 – < 22.5 | 110
// 22.5 – < 25 | 100
// 25 – < 30 | 92.5
// 30 – < 35 | 85
// 35 – < 40 | 77.5
// 40 – < 45 | 70
// 45 – < 50 | 65
// 50 – < 55 | 60
// 55 – = 60 | 50
var densityMap = [
{ threshold: 60, class: 50 },
{ threshold: 55, class: 55 },
{ threshold: 50, class: 60 },
{ threshold: 45, class: 65 },
{ threshold: 40, class: 70 },
{ threshold: 35, class: 77.5 },
{ threshold: 30, class: 85 },
{ threshold: 25, class: 92.5 },
{ threshold: 22.5, class: 100 },
{ threshold: 18, class: 110 },
{ threshold: 15, class: 125 },
{ threshold: 12, class: 150 },
{ threshold: 10, class: 175 },
{ threshold: 8, class: 200 },
{ threshold: 6, class: 250 },
{ threshold: 4, class: 300 },
{ threshold: 2, class: 350 }
];
var densityThresholds = densityThresholdsStr.split(',').map(function(val) { return parseFloat(val.trim()); }).sort(function(a, b) { return b – a; }); // Sort descending
var baseClass = 400; // Default for very low density
// Use provided thresholds if custom is selected, otherwise use standard mapping
if (densityThresholdsStr === "2.0, 4.0, 6.0, 8.0, 10.0, 12.0, 15.0") { // Standard DOT (approximate mapping)
densityMap = [
{ threshold: 60, class: 50 }, // If density >= 60, class 50
{ threshold: 45, class: 55 }, // if density 45-59.9, class 55
{ threshold: 35, class: 60 }, // if density 35-44.9, class 60
{ threshold: 25, class: 65 }, // if density 25-34.9, class 65
{ threshold: 15, class: 70 }, // if density 15-24.9, class 70
{ threshold: 10, class: 77.5 }, // if density 10-14.9, class 77.5
{ threshold: 8, class: 85 }, // if density 8-9.9, class 85
{ threshold: 6, class: 92.5 }, // if density 6-7.9, class 92.5
{ threshold: 4, class: 100 }, // if density 4-5.9, class 100
{ threshold: 2, class: 110 } // if density 2-3.9, class 110
// Anything below 2 lbs/ft³ defaults to a higher class, e.g., 125 or 150 in some schemes
];
baseClass = 125; // Default for density < 2
for (var i = 0; i = densityMap[i].threshold) {
baseClass = densityMap[i].class;
break;
}
}
} else if (densityThresholdsStr === "5.0, 7.0, 9.0, 11.0, 13.0, 15.0, 18.0") { // Custom Set 1 (example)
densityMap = [
{ threshold: 18, class: 65 },
{ threshold: 15, class: 70 },
{ threshold: 13, class: 77.5 },
{ threshold: 11, class: 85 },
{ threshold: 9, class: 92.5 },
{ threshold: 7, class: 100 },
{ threshold: 5, class: 110 }
];
baseClass = 125; // Default for density < 5
for (var i = 0; i = densityMap[i].threshold) {
baseClass = densityMap[i].class;
break;
}
}
} else {
// Fallback or generic interpretation if thresholds are not standard
// Using a simpler progressive density scale for generic inputs
baseClass = 400; // Default for very low density
if (weightPerCubicFoot >= 500) baseClass = 50;
else if (weightPerCubicFoot >= 450) baseClass = 55;
else if (weightPerCubicFoot >= 400) baseClass = 60;
else if (weightPerCubicFoot >= 350) baseClass = 65;
else if (weightPerCubicFoot >= 300) baseClass = 70;
else if (weightPerCubicFoot >= 250) baseClass = 77.5;
else if (weightPerCubicFoot >= 200) baseClass = 85;
else if (weightPerCubicFoot >= 180) baseClass = 92.5;
else if (weightPerCubicFoot >= 150) baseClass = 100;
else if (weightPerCubicFoot >= 120) baseClass = 110;
else if (weightPerCubicFoot >= 100) baseClass = 125;
else if (weightPerCubicFoot >= 90) baseClass = 150;
else if (weightPerCubicFoot >= 80) baseClass = 175;
else if (weightPerCubicFoot >= 70) baseClass = 200;
else if (weightPerCubicFoot >= 60) baseClass = 250;
else if (weightPerCubicFoot >= 50) baseClass = 300;
else if (weightPerCubicFoot >= 40) baseClass = 350;
else if (weightPerCubicFoot >= 30) baseClass = 375;
else baseClass = 400;
}
// — Factor Adjustments (Simplified) —
// These are example increments. Actual adjustments are complex and vary by carrier.
var classAdjustment = 0;
// Value Adjustment (example: add 5 classes for every $10/lb value over $1)
if (valuePerPound > 1) {
classAdjustment += Math.floor((valuePerPound – 1) / 10) * 5;
}
// Handling, Stowability, Exposure Adjustments
classAdjustment += handlingFactor;
classAdjustment += stowabilityFactor;
classAdjustment += exposureFactor;
var finalClass = baseClass + classAdjustment;
// Ensure final class doesn't exceed maximum (e.g., 400 or higher)
if (finalClass > 400) {
finalClass = 400; // Cap at 400 for standard classes, or adjust if considering higher
}
if (finalClass < 50) {
finalClass = 50; // Minimum class is typically 50
}
resultDiv.innerHTML = "Estimated Freight Class: " + finalClass;
resultDiv.classList.add("success");
}