In Less-Than-Truckload (LTL) shipping, the National Motor Freight Classification (NMFC) system uses "Freight Class" to standardize pricing. While four factors determine class—density, stowability, handling, and liability—density is the primary metric for most commodities.
To calculate your shipment's density (measured in Pounds per Cubic Foot or PCF), follow these steps:
Measure the Dimensions: Measure the length, width, and height of the shipment in inches (including pallets or packaging).
Calculate Cubic Inches: Multiply Length x Width x Height.
Convert to Cubic Feet: Divide the total cubic inches by 1,728 (the number of cubic inches in a cubic foot).
Determine PCF: Divide the weight of the shipment by the total cubic feet.
Freight Class Density Table
Density (PCF)
Freight Class
Less than 1
400
1 to 2
300
2 to 4
250
4 to 6
175
6 to 8
125
8 to 9
110
9 to 10.5
100
10.5 to 12
92.5
12 to 13.5
85
13.5 to 15
77.5
15 to 22.5
70
22.5 to 30
65
30 to 35
60
Greater than 35
55
Example Calculation
Suppose you have a pallet that is 48″L x 40″W x 48″H and weighs 650 lbs.
Volume: 48 x 40 x 48 = 92,160 cubic inches.
Cubic Feet: 92,160 / 1,728 = 53.33 cu ft.
Density: 650 lbs / 53.33 cu ft = 12.19 PCF.
Based on the table, 12.19 PCF falls into Class 85.
Note: Always round up dimensions to the nearest inch and use actual scale weight to avoid re-weighing fees from carriers.
function calculateFreightClass() {
var length = parseFloat(document.getElementById('f_length').value);
var width = parseFloat(document.getElementById('f_width').value);
var height = parseFloat(document.getElementById('f_height').value);
var weight = parseFloat(document.getElementById('f_weight').value);
if (isNaN(length) || isNaN(width) || isNaN(height) || isNaN(weight) || length <= 0 || width <= 0 || height <= 0 || weight <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
var cubicInches = length * width * height;
var cubicFeet = cubicInches / 1728;
var pcf = weight / cubicFeet;
var freightClass = "";
if (pcf < 1) { freightClass = "400"; }
else if (pcf < 2) { freightClass = "300"; }
else if (pcf < 4) { freightClass = "250"; }
else if (pcf < 6) { freightClass = "175"; }
else if (pcf < 8) { freightClass = "125"; }
else if (pcf < 9) { freightClass = "110"; }
else if (pcf < 10.5) { freightClass = "100"; }
else if (pcf < 12) { freightClass = "92.5"; }
else if (pcf < 13.5) { freightClass = "85"; }
else if (pcf < 15) { freightClass = "77.5"; }
else if (pcf < 22.5) { freightClass = "70"; }
else if (pcf < 30) { freightClass = "65"; }
else if (pcf < 35) { freightClass = "60"; }
else { freightClass = "55"; }
document.getElementById('res_volume').innerHTML = cubicFeet.toFixed(2) + " cu ft";
document.getElementById('res_density').innerHTML = pcf.toFixed(2) + " lbs/cu ft";
document.getElementById('res_class').innerHTML = "Class " + freightClass;
document.getElementById('freightResults').style.display = "block";
}