One of the most frustrating experiences for shippers is receiving an invoice that is higher than the quote. You weighed the box, it was 5 kg, but the carrier billed you for 15 kg. Why?
This discrepancy is the number one cause of shipping billing disputes.
Carriers calculate shipping costs based on chargeable weight. This is determined by comparing two numbers and billing for whichever is higher:
Imagine shipping a pillow versus a dumbbell. The pillow is light but huge; the dumbbell is small but heavy. Carriers have limited space in their cargo holds. If they charged only by weight, a plane full of feather pillows would be full but generate very little revenue.
To compensate, "Low Density Cargo" (large, lightweight items) is billed based on volume rather than scale weight.
Carriers will not correct larger than actual dimensions nor higher than actual weight!
Most carriers consider the chargeable weight to be the highest of:
The Actual (scale) weight
Declared weight (what you recorded when preparing the waybill)
Dimensional weight
Declared weight (dimensions you recorded when preparing the waybill)
In other words, if you inadvertently put in larger dimensions or a heavier weight, the carrier will not correct it downward. Of course, if you under declare the weight or dimensions, they will correct upward to actual weight and dimensions. We advise shippers to declare and actual weight and - when in question - round down. The carrier correct the actual weight and dimensions only when the declared weight and dimensions are less than actual.
Use this tool to estimate your chargeable weight before you ship. This formula uses the standard divisor of 5000 (common for express couriers).
Note: Always round your dimensions up to the nearest whole centimeter before calculating.
Most international air carriers use the "5000 divisor" formula. Here is a real-world example of how the math works against the scale:
Scenario: You are shipping a box of plastic toys.
Even though the box only weighs 5 kg, you will be billed for 14 kg.
Accuracy is critical. If you mistakenly declare 10 kg on the waybill when the package is actually 1 kg, the carrier allows their system to bill the declared 10 kg. However, if you declare 1 kg and it actually weighs 10 kg, they will audit and upcharge you.
Pro Tip: Carriers rarely issue credits for over-declared shipments. Always measure twice, verify the "greater of" weight, and declare accurately. This was mentioned above but worth repeating!
Shippers are often surprised when they record what they be believe to accurate yet is actually a fraction more. For example, 5.01 kilograms would be be charged 5.5 kilograms. This can be particularly impactful when it comes to dimensions. Our advice is round down for the carriers but round up when estimating potential costs.
The formula above is standard for courier and parcel shipments.
However, other modes of transport utilize different calculations:
Don't let volume weight eat into your margins. Our logistics experts provide personalized support to ensure your shipments are classified correctly, routed efficiently, and fully compliant.
Need to measure a package but missing a tape measure? Use our printable tools: