A dense pallet and a bulky, light one can leave on the same aircraft and bill on completely different logic.
Chargeable weight, not scale weight, is the base of the bill
IATA's own explainer states the rule in one line: “Whichever is higher, the volumetric weight or actual weight, that is the amount that will be used for pricing the air freight cost.” (iata.org, read 2026-08-31). The volumetric side is worked out with an industry-standard formula — length times width times height in centimeters, divided by 6,000 — and the airline or forwarder compares that figure against the shipment's actual scale weight, then bills the larger of the two.
Run a box that measures 60 by 50 by 40 centimeters through the formula: 60 × 50 × 40 = 120,000, divided by 6,000, comes to 20 kilograms of volumetric weight. If that same box weighs 15 kilograms on the scale, it still bills at 20 kilograms — the cubic space it occupies on the aircraft costs more than the mass it adds. Freightos' guide gives a second worked example along the same lines: a 40 by 40 by 40 centimeter box weighing 5 kilograms is billed as 10.67 kilograms once the volumetric figure is run (freightos.com, read 2026-08-31). Pack dense, and the scale weight is what you pay on. Pack bulky, and the outside dimensions are.
This is the same greater-of logic our cross-border pallet guide works through in full with a worked pallet-sized table against DHL Global Forwarding's published divisors, and it is why a crate leaving the country prices the way our crate-overseas guide describes rather than by a flat rate. This page does not repeat either table — it is the air-only explainer both of those only gesture at.
What moves the per-kilogram number after chargeable weight is set
Once chargeable weight is fixed, four things move the rate applied to it, and none of them is under a shipper's control the way packing density is. Every figure below is Freightos' own published range, read 2026-08-31, not a rate this site can quote.
Fuel surcharges ride on top
Freightos states fuel surcharges typically run 15 to 30 percent of the base rate. Flexport's own methodology page describes the mechanism behind it: the surcharge is calculated using a base fuel or threshold price, a base fuel mileage figure, and price fluctuation against that baseline (flexport.com, read 2026-08-31) — reset on a schedule, not held flat between rate filings.
Route density sets the floor
Freightos reports that high-frequency lanes with several competing carriers, the kind that connect major hubs, can price 20 to 30 percent cheaper per kilogram than a thin route with limited lift. A secondary lane with one operator has less competition pushing the rate down.
Peak season adds a premium
Freightos names November through January as the peak window, when rates climb 30 to 50 percent above off-peak averages, especially on transpacific lanes — the same weeks retail volume is heaviest and belly capacity on passenger aircraft is tightest.
Speed and cargo type add their own lines
Express or priority air service adds a 20 to 40 percent premium over deferred service on the same lane per Freightos, and dangerous-goods cargo carries its own 10 to 25 percent surcharge above the base rate for the extra handling and documentation it requires.
None of these stack in a fixed order, and a real quote reflects all of them at once against a specific lane on a specific week — which is exactly why nobody, this site included, prints a single air freight rate card.
Who you book through changes the number too
The same chargeable weight, on the same lane, in the same week, does not cost the same depending on the channel it is booked through. Freightos lays out three: an airline booked direct, a freight forwarder, or a digital marketplace, and states plainly that freight forwarder platforms typically carry a 15 to 25 percent markup on raw airline rates (freightos.com, read 2026-08-31).
| Channel | What it trades |
|---|---|
| Airline, booked direct | Closest to the raw rate, but needs an existing account and enough volume to be worth an airline's sales desk quoting it individually. |
| Freight forwarder | A 15 to 25 percent markup over the raw airline rate, in exchange for consolidation, documentation handling, and a quote available to a shipper with no direct airline account. |
| Digital marketplace | Instant comparison across contract, allotment and spot rates from many carriers at once, trading a sales relationship for speed and visibility into the spread. |
A forwarder's markup is not padding for its own sake — it is what a shipper pays for someone else owning the customs paperwork, the consolidation math, and the relationship with an airline that a one-off shipper does not have. Comparing more than one channel, on the same real cargo, is the only way to know which trade is worth it for a given shipment.
What SMKlog prices here, and what it routes onward
SMKlog's calculator quotes US domestic parcels through USPS, UPS and FedEx by ZIP code and weight, and none of the figures above come from it — they are IATA's and Freightos' own published ranges, cited for what moves an air cargo rate, not a quote for a specific shipment. An air freight lane, international or domestic, needs its own weight, dimensions, commodity and route in front of a forwarder before a real number exists; SMKlog does not arrange air freight. Our cheap freight shipping guide covers the same no-invented-price approach for domestic LTL, and our freight forwarders guide covers what a forwarder actually does with the markup described above.
Where these figures come from
- IATA (International Air Transport Association), Air Cargo Tariffs and Rules: What You Need to Know — the greater-of weight rule, the 6,000 volumetric divisor, and the 0.50 to 5.00 USD per kilogram cost range. Read 2026-08-31.
- Freightos, Air Cargo Price per KG: Complete Guide to Air Freight Rates in 2026 — the fuel surcharge, peak season, route density and dangerous-goods surcharge ranges, the worked volumetric example, and the freight forwarder markup figure. Last updated by Freightos July 2, 2026, read 2026-08-31.
- Flexport, The Cost of Air: Your Guide to Airfreight Rates & How to Reduce Them — the fuel surcharge calculation mechanism. Read 2026-08-31.
Air cargo rates move week to week against fuel prices, capacity and demand on the specific lane. Treat every range above as what these three sources published on the date shown, and get a lane quoted fresh rather than working backward from an old figure.
Air freight pricing questions
How much does air freight cost per kilogram?
IATA states international air freight runs roughly 0.50 to 5.00 USD per kilogram or more depending on the cargo (iata.org, read 2026-08-31). Freightos tracked one Shanghai to Chicago lane moving between 3.50 and over 7.00 USD per kilogram inside a single week (freightos.com, read 2026-08-31). Neither number is a quote for a specific shipment, and no forwarder prices one without a real weight, dimensions and route in front of them.
Is air freight priced by actual weight or by size?
Whichever produces the higher figure. IATA's own explainer states that whichever is higher, the volumetric weight or the actual weight, is the amount used for pricing the air freight cost, with volumetric weight worked out by dividing the shipment's cubic centimeters by 6,000. A bulky, light pallet routinely bills on its size rather than its scale weight.
Does booking through a freight forwarder cost more than booking an airline directly?
Usually, and that markup buys something. Freightos' own pricing guide states that freight forwarder platforms typically carry a 15 to 25 percent markup on raw airline rates, in exchange for consolidating volume, handling documentation, and quoting a shipper who has no direct account with an airline.
Why does the same lane quote a different price two weeks apart?
Fuel surcharges reset against a moving fuel index rather than a fixed schedule, and Freightos' own data shows fuel surcharges typically running 15 to 30 percent of the base rate, with peak-season demand from November through January pushing rates 30 to 50 percent above off-peak averages on the same route. Route density moves it too: high-frequency lanes with several competing carriers price 20 to 30 percent below a thin route with limited capacity.
Can SMKlog quote an international air freight shipment on the calculator?
No. The calculator prices US domestic parcels through USPS, UPS and FedEx. SMKlog sells parcel labels only and does not arrange pallet or freight shipments.