This is the weight used by carriers for billing purposes if it's greater than the actual weight.
Understanding and Calculating Dimensional Weight
Dimensional weight, often referred to as "dim weight" or "volumetric weight," is a standard used by shipping carriers to determine the billable weight of a package. It's calculated based on the package's dimensions (length, width, and height) rather than its actual, physical weight. Carriers use dim weight to account for the space a package occupies in a delivery vehicle, as larger, lighter packages can be just as costly to transport as smaller, heavier ones.
How Carriers Use Dimensional Weight
When you ship a package, carriers will compare the package's actual weight with its calculated dimensional weight. The higher of the two values is typically used as the billable weight. This means that even if your package weighs only 5 pounds, but its dimensions result in a dim weight of 10 pounds, you will likely be charged for 10 pounds.
The Formula for Dimensional Weight
The formula for calculating dimensional weight is straightforward:
Length, Width, Height: These are the measurements of the longest side, the second longest side, and the shortest side of the package, respectively. It's crucial to use consistent units for all three measurements (e.g., all in inches or all in centimeters).
Divisor: This is a number set by each shipping carrier. The divisor varies between carriers and can also change over time. Common divisors for shipments in inches are 139 (used by UPS and FedEx for many services) and 166. For shipments measured in centimeters, a common divisor is 5000. It's always best to confirm the current divisor with your specific carrier.
Steps to Calculate Dimensional Weight
Measure Your Package: Accurately measure the length, width, and height of your package. Ensure you are using the outermost points of the package.
Ensure Consistent Units: Make sure all three measurements are in the same unit (e.g., inches or centimeters). If they are not, convert them to a common unit before proceeding.
Identify the Carrier's Divisor: Determine the correct divisor for the shipping service you are using.
Calculate: Multiply the length, width, and height, then divide the result by the carrier's divisor.
Compare: Compare the calculated dimensional weight to the package's actual weight. The higher value is the billable weight.
Example Calculation
Let's say you are shipping a package with the following dimensions and using a carrier that uses a divisor of 139:
If the actual weight of this package is 18 pounds, the dimensional weight (21.58 pounds) is higher. Therefore, the billable weight for this shipment would be approximately 21.58 pounds.
Why Dimensional Weight Matters
Understanding and accurately calculating dimensional weight can help businesses:
Estimate Shipping Costs: More accurately predict shipping expenses, especially for bulky items.
Optimize Packaging: Encourage the use of smaller boxes for lighter items to reduce shipping costs.
Avoid Surprises: Prevent unexpected charges from carriers.
By using this calculator and understanding the principles behind dimensional weight, you can make more informed decisions about your shipping operations.
function calculateDimensionalWeight() {
var length = parseFloat(document.getElementById("length").value);
var width = parseFloat(document.getElementById("width").value);
var height = parseFloat(document.getElementById("height").value);
var divisor = parseFloat(document.getElementById("divisor").value);
var lengthUnit = document.getElementById("lengthUnit").value;
var widthUnit = document.getElementById("widthUnit").value;
var heightUnit = document.getElementById("heightUnit").value;
var resultDiv = document.getElementById("result");
var resultValueDiv = document.getElementById("result-value");
// Clear previous results and styling
resultDiv.style.display = 'none';
resultValueDiv.textContent = ";
// Input validation
if (isNaN(length) || isNaN(width) || isNaN(height) || isNaN(divisor)) {
alert("Please enter valid numbers for all dimensions and the divisor.");
return;
}
if (length <= 0 || width <= 0 || height <= 0 || divisor <= 0) {
alert("Dimensions and divisor must be positive numbers.");
return;
}
// Unit conversion to a common base (e.g., inches for calculation, assuming standard US carriers)
// However, for dim weight, the units of L, W, H determine the units of the result.
// The formula is (L * W * H) / Divisor. If L, W, H are in inches, the result is in lbs (if divisor is designed for lbs).
// If L, W, H are in cm, the result is in kg (if divisor is designed for kg).
// Our calculator assumes a consistent unit for L, W, H and the divisor.
// The common practice is to use inches and a divisor that yields pounds, or cm and a divisor that yields kg.
// We will assume the user has selected compatible units for their divisor.
// For simplicity in this calculator, we'll just use the provided units and divisor.
var volume = length * width * height;
var dimensionalWeight = volume / divisor;
// Display the result
resultValueDiv.textContent = dimensionalWeight.toFixed(2); // Display with 2 decimal places
resultDiv.style.display = 'block';
}