CBM Calculator — Cubic Meter Volume for Freight Shipping
Answer: CBM = (length × width × height in meters) × quantity. For cm, divide the product by 1,000,000. For inches, multiply by 0.0000164.
What is CBM?
CBM (cubic meter, m³) is the volume of a shipment, used by ocean-freight LCL and air-freight carriers to price cargo. Rates are quoted per CBM, or per the heavier of CBM-equivalent and actual weight (known as chargeable weight).
How the calculator works
For each carton type, enter length, width, height, and quantity. The calculator converts your unit to meters, multiplies L × W × H to get the volume of one carton, then multiplies by quantity. It sums every carton type and outputs the total in m³ and ft³.
If your cartons come in different sizes, use + Add carton type to add another row. Each row computes independently, then the total is the sum.
CBM formula by unit
| Input unit | Formula for one carton |
|---|---|
| cm | (L × W × H) ÷ 1,000,000 |
| m | L × W × H |
| in | L × W × H × 0.0000164 |
| ft | L × W × H × 0.0283168 |
Then multiply by carton quantity.
Container capacity reference (as of April 2026)
| Container | Internal volume | Usable CBM (≈85% load factor) |
|---|---|---|
| 20ft GP | 33 m³ | ~28 m³ |
| 40ft GP | 67 m³ | ~58 m³ |
| 40ft HQ | 76 m³ | ~65–68 m³ |
| 45ft HQ | 86 m³ | ~73 m³ |
Actual usable capacity depends on carton dimensions and packing efficiency. For a more precise estimate, the FCL vs LCL break-even calculator (coming soon) will help you decide whether to book a full container or ship LCL by CBM.
Example
Your order: 80 cartons, each 50 × 40 × 30 cm.
- One carton volume: 50 × 40 × 30 = 60,000 cm³ = 0.06 m³
- Total CBM: 0.06 × 80 = 4.8 m³
- If your total weight is 480 kg, your chargeable weight for ocean LCL is max(4.8 CBM, 0.48 tonnes) = 4.8 CBM at the 1000 kg/m³ standard.
FAQs
What does CBM mean in shipping? CBM means cubic meter. It measures shipment volume, not weight, and is the main billing unit for ocean LCL freight.
Do I use product size or carton size? Use the packed outer carton size, including tape, labels, and any bulging edges. Forwarders quote from the measured export carton, not the inner product.
How many CBM fit in a 40HQ container? A 40HQ has about 76 m³ internal volume, but practical usable capacity is usually 65–68 CBM after aisle gaps, carton fit, and loading limits.
Why is my forwarder charging by CBM when my cargo is heavy? For ocean LCL, carriers usually compare CBM with metric tons at a 1 CBM = 1000 kg standard. If your cargo is under 1000 kg per CBM, volume wins.
Can CBM tell me the final freight cost? No. CBM gives the volume line. Final freight also depends on lane, Incoterms, cargo type, local charges, customs, and delivery address.
Dated facts (as of May 2026)
- China-US ocean LCL quotes commonly use a 1 CBM minimum, even when the measured shipment is smaller.
- A 20ft GP container is usually planned at about 28 usable CBM, while a 40HQ is usually planned at 65-68 usable CBM for boxed ecommerce cargo.
- For air freight, CBM alone is not the billing unit; carriers convert volume to dimensional weight using 6000 cm³/kg for IATA air or 5000 cm³/kg for many courier services.
Related calculators
If you already know the shipment volume, use the chargeable weight calculator to compare actual and volumetric weight, the volumetric weight calculator for air freight for IATA 6000 vs courier 5000 divisor checks, and the LCL ocean freight calculator when you need to turn CBM into an ocean-freight estimate.
When CBM isn’t enough
CBM alone doesn’t price your freight — you also need origin/destination ports, Incoterms, and cargo type (general, battery, liquid, dangerous). Use the calculator to lock the volume number, then request a live quote for the full rate.
Frequently asked questions
- What is CBM in shipping?
- CBM stands for cubic meter and is the volume of your shipment in m³. Ocean freight LCL and air freight carriers quote rates based on CBM (or the higher of CBM × 1000 kg/m³ and actual weight, known as chargeable weight).
- How do I calculate CBM for multiple cartons?
- Calculate the CBM of one carton (L × W × H in meters), then multiply by the number of cartons. If cartons have different dimensions, calculate each carton type separately and sum the totals.
- What is 1 CBM equal to?
- 1 CBM (cubic meter) equals 35.315 cubic feet, or 1,000,000 cubic centimeters. For ocean LCL pricing, 1 CBM is the standard volume unit.
- Is CBM the same as volumetric weight?
- No. CBM is pure volume. Volumetric weight converts CBM to a kg value using a carrier-specific divisor (6000 for air IATA, 5000 for courier, 1000 for ocean LCL). Carriers charge the higher of actual weight and volumetric weight.
- How many CBM fit in a 20ft container?
- A 20ft GP container holds about 28 CBM usable (33 CBM internal volume, ~85% load factor). A 40ft GP holds ~58 CBM, and a 40ft HQ ~68 CBM. Actual capacity depends on packing efficiency.
- Do I use outer carton or inner dimensions?
- Always use outer carton dimensions for freight CBM — that is what the carrier measures when they load. Inner dimensions are for product fit, not shipping cost.