Air freight vs sea freight from China: how to choose

Most shipment decisions begin with a price per kilo. The two modes are priced on different bases, so the smaller figure often belongs to the shipment that ends up costing more.

Getting the comparison right matters for cargo leaving Yiwu, Ningbo, Shanghai and Shenzhen. A wrong call either pays for speed nobody needed or leaves stock on the water while a listing runs dry.

What each mode charges for

Air freight is billed on chargeable weight. The carrier compares the actual weight of the cargo with the space it occupies and charges whichever is greater. A carton of cushions and a carton of hardware can weigh the same and cost very different amounts to fly, because one takes up far more room in the aircraft.

Sea freight is billed by volume for LCL cargo, in cubic metres, or by the container for FCL. Weight enters the calculation only when cargo is dense enough to hit a limit before the space runs out, which is common with tiles, fittings and machinery.

A per-kilo figure lifted from an air quote therefore tells you little on its own. It ignores the room your cartons take up, the minimum charge applied to a small shipment, and everything that happens after the aircraft lands.

Air also has tighter limits on the size and weight of a single piece, and cargo that will not fit the handling equipment at either airport gets refused or repriced after screening. Sea freight absorbs oversize cargo far more easily, which matters for long profiles, machinery and anything loaded on a tall pallet.

Transit times on our lanes

These are the ranges we give customers for cargo leaving China on our own routes:

United States: 25 to 35 days by sea, 7 to 10 days by air
Canada: 28 to 38 days by sea, 10 to 15 days by air
United Kingdom: 30 to 35 days by sea, 10 to 15 days by air
European Union: 28 to 40 days by sea, 10 to 15 days by air
Australia: 15 to 25 days by sea, 10 to 15 days by air
South Africa: 22 to 30 days by sea, 12 to 18 days by air
Japan: 7 to 10 days by sea, 5 to 7 days by air
UAE and the Middle East: 18 to 25 days by sea, 8 to 15 days by air

Those ranges cover time in transit. Clearance, duty payment and the inland leg to your address sit on top, which is why stock planning should use the door-to-door figure. A route with a transshipment adds a second loading and discharge, and the range widens at that point.

For small urgent consignments we also run express services with 3-5 day delivery, which suits samples and a short restock that cannot wait for a consolidated air booking.

Rail is the third option on the Europe and Central Asia lanes. It runs faster than sea and costs less than air, so an order that is too late for the water and too expensive to fly has somewhere to go.

The test that decides it

The freight invoice tells you what each mode costs to move. The decision needs a second number: the air premium per unit sold, set against the margin that unit earns.

Subtract the delivered cost by sea from the delivered cost by air, then divide by the units in the shipment. What comes out is the price of speed per unit. Small next to the unit margin, air is buying time cheaply. Close to the whole margin, the shipment needs another reason to fly.

Cargo worth a few dollars a kilo seldom flies. Furniture, tiles, packaging, steel fittings and building materials carry a freight bill larger than the goods are worth, and no delivery date fixes that arithmetic. Cargo where a single unit sells for many times its shipping cost behaves differently: consumer electronics, phone accessories, cosmetics, small runs of branded apparel. On that cargo a launch date or a stockout can make the premium worth paying.

Put a figure on the delay before deciding. Sea freight to some destinations takes 30 days where air takes 10, so air buys roughly 20 extra days of selling. Multiply your daily sales of that item by those 20 days, then compare the result with the premium per unit calculation above. Where the lost sales come out larger, air is the cheaper option despite the bigger invoice.

Two things move the arithmetic while a shipment is under way. Peak season lengthens sea transit and tightens space on the water, so a sailing can land after the range you planned around. A stockout also costs more than the days it lasts once a listing has to rebuild its ranking afterwards.

Minimum charges decide the small end of the range. Air bills a floor for a shipment of a few cartons, and sea LCL does the same in cubic metres, so the published rate per kilo or per cubic metre never applies to a box this size. Below that point the parcel belongs with an express courier.

Splitting one order between the two

Many orders we handle do not travel entirely by one mode. The units that sell first fly, the depth stock sails, and both parts move on one set of commercial documents.

Send the units you need on the shelf this month by air, and the balance by sea on the same booking
Keep one set of commercial invoices for both parts, so the customs entry matches what you actually bought
Consolidate the sea portion at our Yiwu warehouse, where cartons from several suppliers arrive, get checked and leave as one shipment
Insure both legs at the declared value when you book, with the declared figure matching the invoice

The split costs more administration than a single booking. It saves money whenever the alternative is flying a whole order to protect a fraction of it.

Comparing an air quote with a sea quote

Both quotes describe a service, and they rarely describe the same one. A buyer on r/freightforwarding put the trap this way: "the biggest mistake is comparing only the ocean-freight number. Ask every forwarder to quote the exact same scope and list the charges separately."

An air quote leads with a rate per chargeable kilo, then adds fuel and security surcharges and airport handling, often with a minimum charge a small shipment reaches before the rate applies at all. A sea LCL quote leads with a rate per cubic metre and adds origin charges plus destination charges, the latter usually billed by a company in the destination country.

The two documents also stop in different places. One may include pickup and delivery, the other may hand over at the airport or the quay, and duty may sit outside both.

Ask for the identical scope in writing: pickup at the supplier, export clearance, main freight, import clearance, duty and tax, delivery to the address. Then the totals describe the same journey, and the lower one is genuinely lower.

DDP puts that whole scope into one price with one company answerable for it, which removes the comparison problem at the source. We quote air and sea that way, so both figures can be read side by side without adjusting either.

Working through your own shipment

Six details settle most of these decisions:

Carton count, dimensions and gross weight as packed
Units per carton, so the cost per unit can be worked out
Value per unit at the price you sell it
The date the stock has to be live, rather than the date it should leave China
Daily sales or reorder size, so a delay can be priced
Anything about the product that needs approval before it can fly

Send those and we price both modes on the same door-to-door scope with the transit time for the route, usually within 24 hours. If one option looks wrong for your cargo, we say so and explain why.

Yueyang International Logistics has shipped from China since 2010, working out of Yiwu with sea, air and rail freight and DDP door-to-door delivery on routes to the Americas, Europe, Australia, the Middle East and Africa. Reach us at [email protected] or +86 152 6732 4109.