Consider a common scenario: two buyers import the same throw at the same FOB price, yet their ocean freight cost per piece comes out noticeably different. The difference is rarely the forwarder — it is the export carton. Carton dimensions decide how many throws fit in a container, and for a bulky product like throws, packing density is one of the biggest levers on landed cost that many buyers never negotiate.
Ocean freight for full containers is essentially a charge for space: your freight cost per throw is the container freight rate divided by the number of throws that fit inside it. That denominator comes from the export carton — its dimensions and how many pieces each carton holds. Change the carton, and the per-piece freight changes with it. This guide walks through the CBM math, how carton size is chosen, where compression helps and where it destroys the product, and the questions that separate a freight-efficient supplier from an expensive one.
Key takeaways
- Ocean freight for full containers is a space charge, so pieces-per-CBM — not pieces-per-carton — is the number that drives your freight cost per piece.
- Design carton dimensions around the container’s internal dimensions, not around the product alone; a few centimeters in the wrong dimension can cost a whole row of stacking positions.
- Vacuum compression is the biggest single lever on pieces-per-CBM, but it is unsuitable for structured throws, heavy trims, and anything the buyer expects to look plush out of the pack.
- Get packed carton dimensions (L×W×H) and pieces per carton in writing, measured on packed sealed cartons — “standard carton” means nothing.
- Compare suppliers on landed cost per piece, not FOB per piece; a cheaper FOB with a wasteful carton is often the more expensive landed option.
How does CBM math work for throw blankets?
Freight cost per throw equals the container freight rate divided by the number of throws that fit. Work it in three steps: carton CBM (length × width × height in meters); pieces per container (usable volume ÷ carton CBM × pieces per carton, minus a stacking-efficiency allowance); then container rate ÷ pieces per container.
As a concrete example, a 60 × 40 × 40 cm carton is 0.096 CBM — the rest is arithmetic. One number to handle carefully, though: a full container’s usable cargo volume is always below its nominal figure — door clearance, pallet footprints, and imperfect stacking all take their cut. Ask your forwarder for the planning figure for the container type you actually book, rather than costing from a nominal volume found online. And note the charging basis: full-container freight is a flat rate for the box, while LCL (less-than-container) freight is charged by weight or measurement, whichever is higher — the so-called W/M rule, explained in Marine Insight’s ocean freight charges guide. For throws, which are bulky but light, volume almost always governs, which is exactly why the carton matters so much.
How should export carton size be chosen?
Good carton design works backwards from the container, not forwards from the throw: dimensions that divide evenly into the container’s internal space stack with minimal waste, while a carton a few centimeters too long in one dimension can waste a whole row. Keep cartons within handling limits, uniform across SKUs in each load, and matched to palletized or floor-loaded receiving.
- Fit the container grid. Get the internal dimensions of the container type you will actually book from your forwarder, and check that the carton dimensions divide into them cleanly. This is a calculation the factory should be able to show you — a factory that has done this before will produce a loading plan without being asked twice.
- Respect handling limits. Cartons much over roughly 20–25 kg — the handling limit many warehouses work to — become a damage and labor problem. Confirm the limit against your buyer’s warehouse rather than assuming it. Throws are light, so this usually caps pieces per carton before volume does — confirm the packed carton weight, not just the dimensions.
- Keep cartons stackable. Uniform carton sizes across the SKUs in a container load stack cleanly; mixed carton sizes waste space and crush. If a shipment mixes throws, cushions, and rugs, ask the factory for a mixed-loading plan, not just individual carton specs.
- Mind the pallet question. Some buyers receive palletized, some floor-loaded — and palletized loading loses container space to the pallets themselves. Know which one your freight quote assumes before comparing quotes.
When does compression packing pay off?
Compression raises pieces-per-CBM, and vacuum compression is the biggest single lever for throws — but also the most common source of “bulk doesn’t look like the sample” disputes, since the approved sample was never compressed. Match the method to the construction, and never compress a product the buyer expects to look plush out of the pack.
| Packing method | Density gain | Best for | Do not use for |
|---|---|---|---|
| Flat fold, no compression | Baseline | Structured throws, waffle weaves, heavy trims | — |
| Roll packing | Moderate gain | Lightweight throws, travel blankets | Throws that must look flat-folded at retail |
| Vacuum compression | Large gain | Plush throws that recover loft, basic fleece | Pom-pom or fringe trims, quilted throws, anything sold as “lofty out of the pack” |
Require a compression-recovery test before approving vacuum packing for bulk: compress a sample the same way bulk will ship, hold it for a representative storage period, open it, and photograph the result after 24 and 48 hours. If the buyer would not accept that look at retail, do not compress. The density gains in the table are directional — the actual gain depends on the throw’s loft and the compression ratio, so run the math from the factory’s packed carton data, not from a rule of thumb. For the full comparison of packing methods and their freight effects, see roll packing vs vacuum packing for throws.
What should buyers ask the factory about cartons?
Treat the export carton as a specified item, not an afterthought. The buyers who get the best freight economics are the ones who specify the carton: five questions separate a freight-efficient supplier from an expensive one, and a factory that cannot answer them clearly is telling you how much attention your freight costs will get.
- Packed carton dimensions and pieces per carton, per SKU — in writing, measured on packed sealed cartons, not estimated from the product size. Carton dimensions on a spec sheet are sometimes the empty flat carton or an estimate; packed and sealed is the only measurement that counts for freight math.
- Whether the carton is designed for the container grid — ask for the loading plan, and for mixed-SKU loads, the mixed-loading calculation rather than an assumption that the cartons will “fit somehow.”
- Compression method and recovery data — if vacuum-packed: what compression ratio, and has recovery been tested on this exact fabric?
- Carton strength — single-wall vs double-wall, and whether the stacking strength suits the buyer’s warehouse; palletized high-stacking needs stronger board.
- Marks and labeling — SKU, color, quantity, and any retailer-required marks printed on the carton, so the warehouse does not open every box to identify contents.
One more question that pays for itself: ask what the factory’s standard carton is before you approve it. Many factories default to whatever carton is in the warehouse, and a carton designed for your product and your container commonly beats the default on space efficiency. Have the answers above verified at pre-shipment inspection — the inspector can measure a sample of sealed cartons and photograph a dimensioned one.
How does carton choice change the supplier comparison?
Compare two quotes for the same throw: one supplier quotes a lower FOB but packs fewer pieces per carton; the other quotes a higher FOB but packs substantially more into the same carton volume. The second can land cheaper despite the higher FOB, because it fits more pieces into the same container space and cuts freight per piece.
The FOB difference is visible on the quote; the carton difference is invisible until you do the math — which is why buyers who skip it systematically overpay. The rule: never compare FOB prices without the carton data beside them. Build a simple comparison sheet with one row per supplier — FOB per piece, pieces per carton, carton CBM, implied freight per piece, landed cost per piece — and make suppliers compete on the last column. In our supplier experience, factories that optimize cartons tend to be the factories that optimize everything else too. For the full cost picture beyond freight, the EXW-to-landed-cost breakdown shows which components to collect per order, and the Incoterms guide explains who pays for what under each term.
Requesting a quote: specs to confirm
Freight quotes go wrong when the carton data is vague. Confirm these with the factory before costing:
- Packed carton dimensions (L×W×H), per SKU. Measured on packed, sealed cartons — not estimated from the product size and not the empty flat carton.
- Pieces per carton and packed carton weight, per SKU. Both numbers, in writing; weight caps pieces before volume does on dense constructions.
- Container-grid fit. Whether the carton is designed around the container’s internal dimensions, with a loading plan — and a mixed-loading calculation for multi-SKU loads.
- Compression method and recovery data. If vacuum-packed: the compression ratio and recovery test results on the actual fabric.
- Carton strength. Single vs double wall, matched to the buyer’s stacking — palletized high-stacking needs stronger board.
- Marks and labeling. SKU, color, quantity, and retailer-required marks on the carton.
- Packing surcharges. Whether the price includes any per-unit surcharge for compression or special packing — confirm per order in the quotation.
Frequently asked questions
How many throw blankets fit in a 40HQ container?
It depends entirely on the throw’s bulk and the packing method — a program of vacuum-compressed throws can load several times more pieces than flat-folded bulky knits. There is no standard number. Get the packed carton dimensions and pieces per carton from the factory, then calculate: usable container volume ÷ carton CBM × pieces per carton, minus a stacking-efficiency allowance.
Does vacuum packing damage throw blankets?
It can, depending on the product. Plush polyester throws generally recover well; natural fibers, quilted constructions, and decorated trims recover poorly or not at all. Always run a compression-recovery test on the actual product before approving vacuum packing for bulk, and photograph the recovered product as the reference the buyer accepts.
Who decides the export carton size — buyer or factory?
In practice the factory proposes and the buyer approves, but the buyer should treat the carton as a specified item, not an afterthought. State your requirements (palletized or floor-loaded, max carton weight, marks) and ask for the loading plan. Buyers who specify the carton get better freight economics than buyers who accept the default.
Should different SKUs share one carton size?
When possible, yes. Uniform cartons stack efficiently and simplify warehouse handling. Where products differ too much in size, group them into two or three carton sizes and plan the container loading as a mix — ask the factory for the mixed-loading calculation rather than assuming the cartons will “fit somehow.”
How do I verify the factory’s carton claims?
Ask for a photo of a packed, sealed, dimensioned carton during pre-shipment inspection, and have the inspector measure a sample of cartons. Carton dimensions on a spec sheet are sometimes the dimensions of the empty flat carton or an estimate — packed and sealed is the only measurement that counts for freight math. The throw blanket size chart is a useful cross-check for how product dimensions relate to packed dimensions.
Sources & further reading
- Marine Insight — How to Calculate Ocean Freight Charges: FCL vs LCL charging basis and the weight-or-measurement (W/M) rule behind the CBM math in this guide.
- Roll Packing vs Vacuum Packing: Freight Impact — the full packing-method comparison for throws and blankets.
- EXW to Landed Cost: Full Cost Breakdown — every cost component between factory gate and warehouse.
- Pre-Shipment Inspection Guide for Home Textiles — verifying carton claims during inspection.
Freight is the quiet half of landed cost, and the carton is the quiet half of freight. Buyers who specify cartons — dimensions, pieces per carton, compression method, loading plan — consistently land throws cheaper than buyers who negotiate FOB alone. Send your target throw specs and destination port, and we will return pricing with the packed carton data and container-loading calculation beside it, so you can compare on landed cost from the first quote.