Why air quotes look different from ground quotes
Air carriers sell limited space on aircraft, and that space is constrained by both weight and volume. A hold can be full of light, bulky goods long before it reaches its weight limit, or reach its weight limit with plenty of empty room. Pricing is built around this, which is why the figure on your quote is based on a chargeable weight rather than simply what the parcel weighs on a scale.
Actual weight, volumetric weight and chargeable weight
Three terms appear on most air quotes.
- Actual weight is the gross weight of the shipment, including packaging.
- Volumetric weight is a weight figure calculated from the size of the shipment, representing the space it takes up.
- Chargeable weight is whichever of the two is higher.
Volumetric weight is found by multiplying length, width and height, then dividing by a divisor set by the carrier. For general air cargo, a divisor of 6,000 cubic centimetres per kilogram is commonly used, which equals 167 kilograms per cubic metre. Express and parcel services often use a smaller divisor such as 5,000, which produces a higher volumetric weight. Always check which divisor your carrier applies, because it changes the result.
A worked example
Take a carton measuring 60 cm by 40 cm by 50 cm that weighs 12 kg.
- Volume: 60 x 40 x 50 = 120,000 cubic centimetres.
- Volumetric weight at a divisor of 6,000: 120,000 / 6,000 = 20 kg.
- Volumetric weight at a divisor of 5,000: 120,000 / 5,000 = 24 kg.
The actual weight of 12 kg is lower than either figure, so you would be charged for 20 kg or 24 kg depending on the divisor. A tighter box of 50 cm by 40 cm by 40 cm has a volume of 80,000 cubic centimetres, which gives 13.3 kg at a divisor of 6,000 (rounded to one decimal place). Cutting empty space is one of the most direct ways to reduce the cost. The same logic applies to ground parcels, where the equivalent ideas are called dimensional weight and billable weight.
Carriers usually round weights up to the next half or whole kilogram, so check the rounding rule as well.
Components of an air freight price
A typical quote combines several parts.
- Base rate per kilogram. This is the core transport charge for the route. It often falls as the chargeable weight rises, with rates quoted in weight bands such as under 45 kg, 45 kg and above, and higher bands after that.
- Minimum charge. Very small shipments are charged a minimum amount, regardless of weight.
- Fuel and security surcharges. These are added per kilogram and change with market conditions. They work in a similar way to the fuel surcharges that road and parcel carriers apply.
- Origin and destination charges. These cover handling, terminal fees, documentation and screening at each end.
- Pickup and delivery. Collection from your premises and final delivery are usually priced separately unless a door-to-door service is quoted.
- Special handling. Dangerous goods, temperature control, oversize items and high-value cargo often carry extra fees.
- Customs and duties. Clearance fees, duties and taxes are not part of the freight rate. They are separate costs, often billed to the receiver or the shipper depending on the agreed terms.
Read the quote line by line, because two offers with the same headline rate can differ once surcharges are added. Ground carriers add similar carrier surcharges.
What makes rates move
Air freight rates are not fixed. Several factors push them up or down.
- Capacity. Available space depends on the number of flights and freighters on a route. When capacity is tight, rates generally rise. When it expands, they often ease.
- Demand and season. Peak periods before major retail events tend to raise rates and make space harder to book, which ties into the general effect of seasonal demand.
- Direction and trade imbalance. Routes with more freight flowing one way than the other typically price differently in each direction.
- Fuel prices. Jet fuel costs feed into surcharges, sometimes with a delay.
- Speed of service. A guaranteed next-flight-out service costs more than a deferred or consolidated one.
- Disruption. Events that reduce capacity, such as airspace closures or supply chain disruptions, can change prices quickly.
- Shipper volume and contracts. A business moving regular volume may negotiate better terms than an occasional sender. Negotiated terms are common in carrier contracts.
How to reduce the chargeable weight
- Use packaging sized to the product, without large amounts of void fill.
- Choose lighter protective materials where they give equal protection.
- Consolidate several small items into one properly sized carton where it makes sense, rather than sending many separate parcels.
- Confirm the carrier’s divisor and rounding rules before you choose box sizes.
- Compare modes where timing allows, because the price of air per kilogram is usually much higher than that of sea or road.
Never reduce packaging so far that goods are at risk of damage. A saved few kilograms is a poor trade if the item arrives broken.
Reading and comparing quotes
When you compare, ask the same questions each time: What weight is the quote based on? What divisor is used? Which surcharges are included? Is it airport to airport or door to door? Who pays duties and taxes? What transit time is expected, and is it guaranteed or an estimate? Rates change often, so a quote is usually valid only for a limited time, and the final invoice can differ if the measured weight differs from what was declared.