Freight classes are a critical component of the Less Than Truckload (LTL) shipping industry. They are standardized by the National Motor Freight Traffic Association (NMFTA) and used by carriers to determine the price of shipping goods. The class is assigned based on four main characteristics of the freight:
Density: The amount of weight per unit of volume. This is often the most significant factor in determining class.
Stowability: How easily the freight can be loaded and secured with other freight.
Handling: Special equipment or labor required for loading and unloading.
Liability: The risk associated with transporting the freight, including its value and susceptibility to damage or theft.
There are 18 different freight classes, ranging from Class 50 (the lowest class, typically for very dense, stable items) to Class 400 (the highest class, usually for extremely light, bulky, or hazardous items). While a comprehensive class determination involves subjective assessment of all four factors by a carrier, density is often the primary driver, especially for less complex shipments.
How the Freight Class Calculator Works
This calculator focuses on the most dominant factor in freight classification: density. It takes the dimensions and weight of your shipment to calculate its density and then uses a simplified logic to suggest a probable freight class. This calculator is a helpful tool for initial estimation but should always be confirmed with your LTL carrier.
The calculation proceeds as follows:
Calculate Volume: The total volume of the shipment is determined by multiplying its length, width, and height (in feet).
Volume (ft³) = Length (ft) × Width (ft) × Height (ft)
Calculate Density: The density of the shipment is then calculated by dividing its weight (in pounds) by its volume (in cubic feet).
Density (lbs/ft³) = Weight (lbs) / Volume (ft³)
Determine Class Based on Density: The calculated density is then compared against a set of thresholds that generally align with the NMFTA's freight class system. Please note that these are simplified thresholds for estimation purposes, and actual carrier classifications may vary based on the other three factors (stowability, handling, liability).
Class 50: Density > 15.0 lbs/ft³
Class 55: 12.0 to 15.0 lbs/ft³
Class 60: 10.0 to 12.0 lbs/ft³
Class 65: 8.0 to 10.0 lbs/ft³
Class 70: 7.0 to 8.0 lbs/ft³
Class 77.5: 6.0 to 7.0 lbs/ft³
Class 85: 5.0 to 6.0 lbs/ft³
Class 92.5: 4.0 to 5.0 lbs/ft³
Class 100: 3.0 to 4.0 lbs/ft³
Class 110: 2.5 to 3.0 lbs/ft³
Class 125: 2.0 to 2.5 lbs/ft³
Class 150: 1.5 to 2.0 lbs/ft³
Class 175: 1.0 to 1.5 lbs/ft³
Class 200: 0.5 to 1.0 lbs/ft³
Class 250: 0.25 to 0.5 lbs/ft³
Class 300: 0.125 to 0.25 lbs/ft³
Class 400: < 0.125 lbs/ft³
Example Calculation:
Let's say you are shipping a pallet of custom-made furniture components. The pallet measures 4 feet long, 3 feet wide, and 5 feet high. The total weight of the shipment is 1200 lbs.
Volume: 4 ft × 3 ft × 5 ft = 60 ft³
Density: 1200 lbs / 60 ft³ = 20.0 lbs/ft³
Estimated Class: Based on our thresholds, a density of 20.0 lbs/ft³ falls into the Class 50 category (Density > 15.0 lbs/ft³).
Disclaimer: This calculator provides an estimation based on density. Always consult with your LTL carrier for the official freight class determination for your shipment.
function calculateFreightClass() {
var densityInput = parseFloat(document.getElementById('density').value);
var lengthInput = parseFloat(document.getElementById('length').value);
var widthInput = parseFloat(document.getElementById('width').value);
var heightInput = parseFloat(document.getElementById('height').value);
var weightInput = parseFloat(document.getElementById('weight').value);
var resultDiv = document.getElementById('result');
var resultValue = document.getElementById('result-value');
var resultExplanation = document.getElementById('result-explanation');
var calculatedDensity = null;
var freightClass = null;
var explanationText = ";
if (isNaN(densityInput) && (isNaN(lengthInput) || isNaN(widthInput) || isNaN(heightInput) || isNaN(weightInput))) {
resultValue.innerHTML = "Please enter valid inputs.";
resultExplanation.innerHTML = "";
resultDiv.style.display = 'block';
return;
}
if (!isNaN(densityInput)) {
calculatedDensity = densityInput;
explanationText = 'Calculated using the provided density.';
} else if (!isNaN(lengthInput) && !isNaN(widthInput) && !isNaN(heightInput) && !isNaN(weightInput)) {
var volume = lengthInput * widthInput * heightInput;
if (volume <= 0) {
resultValue.innerHTML = "Volume must be greater than zero.";
resultExplanation.innerHTML = "";
resultDiv.style.display = 'block';
return;
}
calculatedDensity = weightInput / volume;
explanationText = 'Calculated density from dimensions and weight.';
} else {
resultValue.innerHTML = "Enter either density or all dimensions and weight.";
resultExplanation.innerHTML = "";
resultDiv.style.display = 'block';
return;
}
if (isNaN(calculatedDensity) || calculatedDensity 15.0) {
freightClass = 50;
} else if (calculatedDensity >= 12.0) {
freightClass = 55;
} else if (calculatedDensity >= 10.0) {
freightClass = 60;
} else if (calculatedDensity >= 8.0) {
freightClass = 65;
} else if (calculatedDensity >= 7.0) {
freightClass = 70;
} else if (calculatedDensity >= 6.0) {
freightClass = 77.5;
} else if (calculatedDensity >= 5.0) {
freightClass = 85;
} else if (calculatedDensity >= 4.0) {
freightClass = 92.5;
} else if (calculatedDensity >= 3.0) {
freightClass = 100;
} else if (calculatedDensity >= 2.5) {
freightClass = 110;
} else if (calculatedDensity >= 2.0) {
freightClass = 125;
} else if (calculatedDensity >= 1.5) {
freightClass = 150;
} else if (calculatedDensity >= 1.0) {
freightClass = 175;
} else if (calculatedDensity >= 0.5) {
freightClass = 200;
} else if (calculatedDensity >= 0.25) {
freightClass = 250;
} else if (calculatedDensity >= 0.125) {
freightClass = 300;
} else {
freightClass = 400;
}
resultValue.innerHTML = freightClass;
resultExplanation.innerHTML = `Density: ${calculatedDensity.toFixed(2)} lbs/ft³. ${explanationText}`;
resultDiv.style.display = 'block';
}