Air or sea freight from China: when is air worth the cost?
Air freight from China is worth it when its extra delivered cost is less than the contribution margin you would lose while waiting for sea freight. Use lost margin, not lost revenue, and count only sales that would really be lost. If only part of the order prevents a stockout, fly that part and ship the rest by sea, with both quoted separately.
The break-even rule
Three inputs decide it: the extra cost of air over sea for the same delivery scope, the number of days earlier the stock becomes usable, and the contribution you would lose per day of waiting. Contribution is the selling price less product cost and variable selling costs, not the price itself. If lost contribution over the gap exceeds the extra cost, air pays for itself.
Add financing costs or contractual late-delivery penalties only if they apply to your business and you can substantiate them. Leave out sales that customers would simply make later, or that another product in your range would capture.
Worked example: what must air save you?
Everything here is hypothetical, including the quotes and dates; these are not market prices or promised transit times. Assume complete transport-and-handling totals to your premises, excluding duty and import VAT, of £1,200 by sea and £3,000 by air, so air costs £1,800 more. Assume air makes stock usable 20 days earlier and each lost sale costs £8 of contribution.
The table shows how the answer turns on the daily lost sales. At 15 a day air wins; at 5 a day it loses. The break-even is 225 otherwise-lost sales across the 20 days, so the decision is really a question about your sales forecast, not your freight quote.
| Sales lost per day while waiting for sea | Contribution saved by air over 20 days | Result of paying £1,800 extra for air |
|---|---|---|
| 15 | 15 × 20 × £8 = £2,400 | £600 better off |
| 5 | 5 × 20 × £8 = £800 | £1,000 worse off |
| Break-even | £1,800 ÷ £8 = 225 sales over the 20 days | No gain or loss |
Getting the inputs right
Days gained means the difference in the date stock is usable at your premises, from the same cargo-ready date, including clearance, delivery and receiving checks; not the flight time against the sailing time. Build both dates with shipping lead-time planning. Extra cost means two complete delivered quotes on the same scope, with air priced on its chargeable weight; comparing freight forwarder quotes covers how to get them. For sailing changes, see handling a rolled freight booking. For checking air shipment paperwork, see how to read an air waybill.
HMRC's guidance includes transport, loading and handling up to entry into the UK in the customs value, and allows air transport costs to be apportioned, so ask your customs agent to show the valuation for each mode rather than assuming the freight difference is the only one. For lithium batteries, the UK CAA says packing, marking, labelling and documentation must follow the ICAO Technical Instructions; get written carrier acceptance before counting air as an option.
Split the order only if the bridge quantity works
Calculate the quantity needed between the expected air arrival and the sea arrival: forecast daily demand × the gap, less usable stock already on hand, plus only the buffer you can justify. Ask for an air quote for that quantity and a fresh sea quote for the rest, because the remaining sea shipment may move from a full container to a shared one, and duplicate handling charges can change the result.
Require separate packing lists and clear carton allocation so the two consignments do not double-count stock. If you want to check the air portion before the factory releases the balance, agree an explicit hold-and-release instruction with the factory in advance. For clothing shipments, see our garment packing for sea freight guide.
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When the answer is neither
For a few cartons, an express courier may beat both; see express courier vs air cargo. If air keeps winning the calculation on the same products, the cheaper fix is usually to reorder earlier or hold more safety stock, both of which the same inputs let you price.
To run your own numbers, use the sea vs air freight calculator. For a deadline-driven order, have the packed dimensions, cargo-ready date, required UK delivery date and minimum bridge quantity ready before discussing urgent orders from China.
Related help: Chinese New Year planner.
Frequently asked questions
When is air freight from China worth paying for?
When the extra delivered cost of air is less than the contribution margin you would lose from sales that would genuinely be missed while waiting for sea freight.
Should I use lost revenue to justify air freight?
No. Use the contribution from sales that would otherwise be lost. In the hypothetical example, £8 contribution per unit means 225 avoided lost sales are needed to cover a £1,800 air premium.
Is there a standard price or transit time for China to UK freight?
No. Use dated quotations for your exact cargo and route, with the same collection-to-delivery scope, charging basis and exclusions for both modes.
Does a small air shipment prove the rest of the order is good?
It tells you about the goods received. If you want it to influence release of the remainder, agree in advance that the factory holds the balance until your checks are complete.