Three importers this week asked me to quote airfreight for cargo they were already shipping by sea.
Same pattern every time. ETAs from China have slipped 20–30% past published schedule, a critical job is now late, and someone in the WhatsApp group said "fly it."
Before I quote anything, I ask one question: what's the unit weight and the box dimensions?
The math most importers skip
Airfreight pricing isn't per-kg the way most importers think. It's chargeable weight — the higher of the two numbers below, whichever is greater:
- Actual weight (gross kg, including packaging)
- Volumetric weight = length × width × height (cm) ÷ 6,000 for IATA
That divisor is the part importers miss. A pallet of ceramic tile, dense electronic enclosures, or anything heavy-and-compact barely moves between the two — actual weight wins, and the cost is roughly what you'd expect.
But a pallet of light, voluminous goods — apparel, foam packaging, plastic homeware, half-empty cartons — can have a volumetric weight 3–4× the actual weight. The airline charges on the volumetric number. The all-in airfreight bill can land 4–6× the sea-freight cost for the same cargo. And you still pay customs duty and last-mile on top — neither of which gets cheaper because you flew it.
What I do before quoting
When an importer asks me to convert, I ask three things on WhatsApp:
- Total cartons or pallets, with dimensions — L × W × H per piece, in cm
- Total actual weight — kg, including packaging
- How late is the original ETA, and what's the cost of being late?
Questions 1 and 2 give me the chargeable weight in 30 seconds. Question 3 tells me whether the conversion is worth quoting at all. If the cargo is dense enough that airfreight is only 1.5–2× the ocean cost, and the lateness is genuinely costing the business, fly it. If the chargeable weight blows out 4–6×, the answer is usually "hold the sea booking, get a firmer arrival ETA from the line, and replan downstream."
This week, two of three importers backed down once we did the math together. The third flew it — the job justified it. Different situation.
The point
Slipping ETAs are real this season. Bunker shortages, Hormuz traffic, and capacity tightness are all stretching schedules. But "fly it" is the question, not the answer. The math has to clear before anyone touches the booking.
If you've got a slipping container you're tempted to convert, send me the dimensions before you ask for quotes anywhere. I'll run the chargeable-weight math and tell you straight whether the conversion is worth it — or whether the better move is to fix the ocean leg and replan.
No charge for the math. The wrong conversion costs a lot more than a five-minute conversation.