Technical Guide

Chargeable Weight & Volumetric Weight: Why is your air freight so expensive?

Paying for air? Understand the IATA volumetric weight rule and learn how to calculate your chargeable weight to reduce your air freight bills to Morocco.

Equipe Casa Horizon

Transitaire agréé

January 20, 2026

Sommaire

Executive Summary

You ordered 50 kg of plush toys or air filters from France or China by air. When receiving the invoice from your freight forwarder, you are stunned to see that you are billed for 150 kg. Calculation error? Scam attempt? No: you have just discovered the chargeable weight rule.

In 2026, with the saturation of air cargo holds and the increase in fuel costs, airlines (RAM Cargo, DHL, Air France) strictly apply the volume ratio. In this article, Casa Horizon explains how to calculate your volumetric weight and, above all, how to optimize your packages so you no longer pay for "air".

✈️ The Concept: Why airplanes don't just weigh kilos?

An airplane has two physical limits: its lifting capacity (weight) and its available space (volume). Imagine filling an airplane with feathers. The plane will be packed full (volume reached), but it will be very light (weight not reached). For the airline, this is a loss of revenue.

It is to balance this ratio that IATA (International Air Transport Association) created Volumetric Weight. The idea is simple: if your goods take up a lot of space while being light, you will be taxed on the space you occupy rather than what you actually weigh.

⚖️ Actual Weight vs Volumetric Weight: The IATA Rule

For each shipment, two weights are calculated:

Actual Weight (Gross Weight): This is what the scale shows when you put your package on it.
Volumetric Weight (Dimensional Weight): This is a theoretical weight calculated from the package dimensions.

The golden rule: The carrier will always bill on the higher value of the two. This is called the Chargeable Weight.

🧮 The Magic Formula

In 2026, the standard formula applied by the majority of freight forwarders and airlines for international freight is as follows:

Volumetric Weight (kg) = Length(cm) × Width(cm) × Height(cm)6000

(Note: Some express carriers like DHL or FedEx sometimes use a divisor of 5000, which makes the volumetric weight even higher and therefore more expensive).

The 1:6 Ratio

In classic air freight, it is considered that 1 m³ = 166.67 kg. If your cubic meter weighs less than that, you fall into volumetric taxation.

📝 Practical Examples

Case A: "Dense" Goods (Ex: Auto Parts)

Actual Weight: 100 kg
Dimensions: 50 × 50 × 40 cm
Calc: (50×50×40)/6000 = 16.6 kg
Result: You pay for 100 kg (Actual > Volumetric).

Case B: "Light" Goods (Ex: Plush Toys)

Actual Weight: 20 kg
Dimensions: 80 × 60 × 50 cm
Calc: (80×60×50)/6000 = 40 kg
Result: You pay for 40 kg (Volumetric > Actual). Your bill doubles!

💡 Pro Tips: How to reduce volumetric weight?

Avoid Void: Choose cartons perfectly adapted to the product size. If you leave 10 cm of empty space at the top of a carton, you are paying for air.
Compress: For textiles or soft products, use vacuum packaging if possible.
Consolidate: Sometimes, grouping several small cartons into one large carton optimizes dead angles and reduces total billed volume.
Check the Divisor: Always ask your forwarder if they use a divisor of 5000 or 6000. At Casa Horizon, we negotiate the most advantageous divisor for our regular clients.

✅ Quick Takeaways: What to remember

Chargeable Weight

The greater of actual weight and volumetric weight.

Standard Calc

(L × W × H) / 6000 for classic air freight.

Air Ratio

1 m³ = 167 kg. Anything lighter is taxed by volume.

Optimization

Compact packaging can reduce transport bill by 30% to 50%.

💡 Conclusion

Mastering the concept of volumetric weight is essential for any importer wishing to use air freight to Morocco. In 2026, cargo hold space management has become so precise that every centimeter counts.

Don't be surprised by unexpected bills upon arrival at Casablanca Airport. By collaborating with Casa Horizon, we audit your dimensions from the supplier's warehouse to suggest packaging optimizations and guarantee you the fairest chargeable weight.

❓ FAQ

Why does my forwarder use 5000 as divisor instead of 6000?

The 5000 divisor is often used by express couriers as they prioritize speed and their planes are often smaller. Classic Cargo traditionally uses 6000.

Does volumetric weight apply to sea freight too?

Yes, but the ratio is different. In sea freight (LCL), the ratio is 1:1 (1 m³ = 1000 kg). This is called Revenue Ton (RT).

What if my package is irregularly shaped?

Customs and airlines always take the maximum dimensions (widest points) to form an imaginary rectangle around the object.

Do pallets count in the calculation?

Absolutely. If your goods are on a palette, you must include the height and weight of the palette in your chargeable weight calculations.

How does Casa Horizon help reduce these costs?

We sometimes offer "re-packaging" services in our consolidation hubs (China, France, Turkey) to eliminate superfluous volumes before shipment to Morocco.

Sources & Références

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