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Sea Freight vs Air Freight from China: How to Choose
Air and sea freight are priced on completely different bases — weight versus volume — which is why the "cheaper" option changes depending on what you’re shipping. Here’s how to work out which one actually saves you money.
Quick summary
Air freight is priced per kilogram and takes days — best for light, urgent, or high-value orders. Sea freight is priced per CBM (cubic metre) and takes weeks — far cheaper for anything bulky or non-urgent. Heavy-but-small items usually favour air; light-but-bulky items usually favour sea.
The Core Difference: Weight vs Volume
Air freight charges by weight (per kg), sometimes using "volumetric weight" if an item is unusually light for its size. Sea freight charges by volume — CBM, or cubic metre — regardless of how light the contents are. This single difference explains almost every air-vs-sea decision:
- A box of steel tools: heavy, compact → often cheaper by air, since it takes up little space
- A box of inflatable toys: light, bulky → often cheaper by sea, since weight is low but volume is high
- Flat-pack furniture: heavy and bulky → almost always sea, since air freight would charge a lot on both counts
Side-by-Side Comparison
| Factor | Air Freight | Sea Freight |
|---|---|---|
| Priced by | Weight (per kg) | Volume (per CBM) |
| Typical transit time | Days | Weeks |
| Best for | Light, urgent, high-value goods | Bulky, heavy, or non-urgent goods |
| Consolidation options | Express cargo booking | LCL (shared container) or FCL (full container) |
| Typical use case | Samples, restocks with a deadline, apparel | Furniture, cartons, equipment, large-volume restocks |
What Is CBM, and Why Does It Matter?
CBM stands for cubic metre — length × width × height of your cargo, converted to metres. Sea freight rates are quoted per CBM, so two shipments of very different weight can cost the same if they take up the same space, and a shipment that’s mostly empty air inside a large box will cost more than expected. This is why repacking to remove wasted space (loose padding, oversized boxes) can meaningfully lower a sea freight quote.
LCL vs FCL — Do You Need a Whole Container?
Most individual and small-business shipments don’t fill a container, so they travel as LCL (less-than-container-load) : your cargo shares a container with other shipments, and you pay only for the CBM you use. FCL (full-container-load) means booking an entire container — usually only worth it once your shipment volume is large enough that FCL pricing beats the equivalent LCL cost, which a forwarder can calculate for you based on your actual cargo.
A Simple Way to Decide
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01
Is it urgent?
If you need it within days, air is usually the only realistic option regardless of cost.
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02
Is it bulky relative to its weight?
Furniture, packaging, cartons of light goods — sea freight’s per-CBM pricing will almost always win.
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03
Is it heavy but compact?
Dense, small items sometimes cost less by air than expected, since they don’t take up much billable volume.
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04
When unsure, send your forwarder the dimensions and weight (or just the product listing) and ask for both quotes side by side — a straight answer costs nothing to ask for.
Frequently Asked Questions
Can I split one order between air and sea?
Yes — many buyers fly the urgent portion of an order and send the rest by sea. Both can run through the same warehouse and the same forwarder.
Is air freight always more expensive than sea?
Not always — for small, heavy, low-volume shipments the gap can be small, and the speed may be worth it. It’s the bulky, light shipments where sea freight’s savings become large.
How is volumetric weight calculated for air freight?
Air carriers charge whichever is higher: actual weight or volumetric weight (a formula based on the parcel’s dimensions). This is why very light but large parcels can still cost more than their actual weight suggests.
Does repacking really reduce my sea freight cost?
Yes. Because sea freight is priced by volume, removing wasted space — oversized boxes, excess padding — directly reduces your CBM and therefore your quote.
Not sure which method fits your shipment?
Send us your item details or dimensions and we’ll quote both — honestly, not just whichever is more profitable for us.