Container Fill & CBM Planner
The pre-booking calculator wholesale buyers actually need: stack your carton specifications into the box and see total CBM, the 20GP/40GP/40HQ plan for that volume, and whether your consignment is volume-bound or weight-bound — before you ask anyone for a rate.
Total CBM is the sum of every carton's L × W × H; boxes needed is that total divided by a container's usable volume — its ISO 668 internal volume reduced by a packing efficiency factor (85% floor-loaded, 78% palletized), because no real load tiles a container perfectly. Enter your lines below and the planner models all three standard box types at once.
The second limit is weight: a 20GP holds far less cargo volume than a 40GP but nearly the same payload, so dense goods (hardware, tiles, stone) become weight-limited and the right plan follows the weight line, not the cube line. The planner flags that condition per box type, then hands you a summary line to paste into the RFQ.
Container Fill & CBM Planner
Enter carton dimensions and quantities per product line — the planner totals your consignment and models 20GP / 40GP / 40HQ box counts with realistic packing efficiency.
| Product / SKU | L (cm) | W (cm) | H (cm) | Cartons | Weight/carton (kg) | Line CBM | |
|---|---|---|---|---|---|---|---|
| — | |||||||
| — |
| Box Type | Usable Volume (85%) | Boxes by Volume | Boxes by Weight | Plan | Est. Fill of Plan |
|---|---|---|---|---|---|
| 20GP20' General Purpose | 28.2 m³ | 0 | — | 0 × 20GP | — |
| 40GP40' General Purpose | 57.5 m³ | 0 | — | 0 × 40GP | — |
| 40HQ40' High Cube | 64.8 m³ | 0 | — | 0 × 40HQ | — |
Add at least one complete line (dimensions and carton quantity) to see the plan.
The Math Behind the Plan, In the Open
Every number the planner shows comes from the formulas below — no hidden rate assumptions, no invented averages. The efficiency factors are planning conventions, and the payload ratings are the ones published in the container fleet matrix on this site.
| Step | Formula / Value | Where It Comes From |
|---|---|---|
| Carton volume | CBM = L × W × H (cm) ÷ 1,000,000 × cartons | One cubic meter equals one million cubic centimeters. The planner works in cm internally and converts inch entries exactly (1 inch = 2.54 cm). |
| Usable container volume | usable m³ = ISO 668 internal volume × packing efficiency | 20GP = 33.2 m³, 40GP = 67.6 m³, 40HQ = 76.2 m³ — the same ISO 668 figures used in the fleet matrix on this site. |
| Packing efficiency | floor-loaded 85% · palletized 78% | Real stuffing never reaches 100%: cartons do not tile perfectly, door areas stay partially clear, and palletized loads lose volume to pallet height and forklift lanes. 85%/78% are the planning conventions used throughout this site's guides. |
| Boxes needed | boxes = max(ceil(total CBM ÷ usable m³), ceil(total kg ÷ payload kg)) | Volume is one limit; payload is the other. Dense cargo crosses the weight line first — the planner flags which line binds. |
| Payload ratings | 20GP 28,250 kg · 40GP 26,730 kg · 40HQ 26,580 kg | Cargo weight limits per this site's published fleet matrix; VGM at the terminal is the enforceable number. |
Reading the Plan Like a Wholesale Operator
Volume-bound vs weight-bound
Light, bulky cargo (furniture, textiles) fills by cube; dense cargo (hardware, tiles, stone) fills by weight. The planner marks a weight-limited plan when the payload line crosses first. A weight-limited plan never “fills” the box visually — that is correct, not a mistake.
Declared vs measured cartons
Plan on supplier-declared dimensions, then re-check against the warehouse tally at consolidation. Declared cartons under-run reality by a few percent on average; holding 5–10% cube in reserve is the standard insurance.
Floor load or pallets — the destination decides
Pallets speed up warehouse receiving but surrender roughly 7 points of efficiency to pallet height and handling clearances. Choose the mode your DC receiving process actually uses, then let the box count follow — never the reverse.
Frequently Asked Questions
Why does the planner reduce container volume instead of dividing raw cubic capacity?
Because raw volume is a geometric ceiling no real load reaches: cartons do not tile the box perfectly, door rows stay partial, and palletized loads lose height to the pallet itself and lanes to move the forklift. The 85% and 78% factors are the planning conventions used across this site's cargo guides; the estimate they produce is deliberately conservative so a plan survives contact with the tally.
How accurate is the plan for a multi-supplier wholesale order?
As accurate as the declared carton data behind it, which is why the tool models the whole consignment line by line. Use it at PO stage to choose equipment and rough the freight budget, then re-run it when cartons are physical and measured. The final load plan is cut at the consolidation tally, and the VGM at the terminal is the enforceable weight — the planner is the discipline that gets you close, not the document that replaces measurement.
My plan is flagged weight-limited — what should I do?
Follow the weight line: it means the cargo reaches the container's ISO payload rating before its usable volume. Options are the smaller box in more count (dense goods often belong in 20GP for exactly this reason), splitting the program into a heavy box and a light box, or trimming the load. What you cannot do is load past the payload rating — VGM is certified per SOLAS and misdeclaration has safety and liability consequences.
Request Commercial Ocean Freight RFQ
Submit your container shipment details to our Ningbo port desk for contracted space and spot carrier pricing within 12 hours.
Last reviewed: September 2026 — ISO 668 volumes and payload ratings follow this site's published fleet matrix; efficiency factors are planning conventions, confirmed per shipment at tally and VGM.