Ask which is cheaper and the answer is always sea. Ask which is right and it depends on four things: the value of the goods, the cost of capital tied up in transit, the consequences of arriving late, and how much stock you are holding to protect against all three.
The straightforward comparison
| | Sea freight | Air freight | |---|---|---| | Cost per kg | Low | High | | Transit time | Weeks | Days | | Suits | Volume, weight, planned replenishment | Urgent, high-value, perishable | | Capital tied up in transit | More | Less | | Emissions per kg | Lower | Higher |
That table is where most decisions stop. It should not be.
The costs that only appear on one side
Inventory in transit is money you cannot use. A shipment spending five weeks at sea is five weeks of working capital sitting in a container. For low-value goods this is irrelevant. For high-value goods it can quietly exceed the freight saving.
Safety stock is the real cost of a long lead time. Longer transit means more buffer stock to cover variability, and buffer stock needs warehousing, insurance and cash. When people compare sea and air on the rate alone, this is the line they forget.
Late arrival is not a freight cost, but it is a cost. A retail line that misses its season is discounted. A component that misses a production slot idles a factory. Neither shows up on a freight invoice.
A practical rule of thumb
Air tends to win when the goods are high value relative to their weight, when the deadline is fixed and expensive to miss, or when the cargo degrades with time. Sea tends to win when volume is high, the schedule is predictable, and a few weeks of transit costs you nothing but patience.
For everything in between — which is most shipments — the honest answer is to price both and compare total cost, not rate.
The option people forget
You do not have to choose the same mode for the whole order. Splitting a shipment — sending an urgent portion by air to cover the immediate need and the balance by sea — is common, sensible, and often much cheaper than flying everything or waiting for all of it.
It also gives you a hedge: if the sea leg is delayed, you are not entirely out of stock.
What we do
When a shipment could reasonably go either way, we quote both, and we set out the landed cost rather than just the freight rate — so you are comparing the numbers that actually matter to your business.
Ask us to price both for your next shipment.