CBM Calculator by Inches, cm & mm

Enter your carton sizes in inches, centimetres or millimetres. The calculator adds up every carton size in your shipment and shows the total CBM, volumetric weight and how much of a 20ft, 40ft or 40ft high cube container you will use. Results update as you type.

Formulas and container data last reviewed: 2 November 2026 by the AsiaCommerce team.

How to calculate CBM

CBM (cubic metre) is the space your cargo takes up in a truck, container or aircraft. To calculate it, convert the length, width and height of one carton to metres, multiply them, then multiply by the number of cartons. If your shipment has several carton sizes, calculate each size separately and add the results.

CBM = length (m) × width (m) × height (m) × number of cartons

CBM calculator by inches

Factories in China usually write packing lists in centimetres, while many buyers in the US and online sellers measure cartons in inches. Multiply length × width × height in inches to get cubic inches, then divide by 61,023.74 to get cubic metres. For cubic feet, divide the cubic inches by 1,728; one cubic metre is about 35.31 cubic feet.

Select "Inches (in)" in the calculator above and every carton line is converted for you, including shipments that mix several carton sizes. You can also switch the weight unit to pounds.

Volumetric weight and chargeable weight

Air carriers and couriers charge by actual weight or volumetric weight, whichever is higher. Light but bulky cartons are therefore charged by their size. In sea freight LCL, the carrier compares your total CBM with your total weight in tonnes and charges the higher number.

Divisors can differ by carrier and contract, so check the rule written in your quotation before you compare prices.

How many CBM fit in a shipping container?

Cartons rarely fill every corner of a container, so the calculator plans with about 85% of the internal volume. Capacity and payload are typical values published by carriers and vary by container owner, age and local road limits.

Shipping from China to Indonesia, Malaysia or the Philippines?

CBM tells you how much space you need, but it does not tell you whether your goods can clear customs. Each market has its own product rules, for example BPOM registration for food and cosmetics in Indonesia, SIRIM certification for certain products in Malaysia, and FDA registration for food, cosmetics and health products in the Philippines. Checking these before the cartons leave China avoids storage charges and delays at the port.

AsiaCommerce is a cross-border procurement partner for businesses buying from China and selling in Southeast Asia. We help you at every step after the calculation:

• Sourcing from China: find and check suppliers, negotiate and inspect quality before loading.
• Procurement to Southeast Asia: freight, import permits and customs clearance into Indonesia, Malaysia or the Philippines.
• Market entry to Southeast Asia: set up your brand in a new market.
• E-commerce distribution: sell and fulfil through Southeast Asian marketplaces.

Comparing forwarders? Read our guide to choosing a logistics company in ASEAN.

Frequently asked questions

What is CBM in shipping?

CBM stands for cubic metre, the volume your cargo occupies. It is the main pricing unit for sea freight LCL and the basis for deciding which container size you need.

How do I calculate CBM from inches?

Multiply length × width × height in inches, multiply by the number of cartons, then divide by 61,023.74. For example, 25 cartons of 24 × 16 × 16 inches equal about 2.52 CBM.

Does CBM affect import duties?

No. Import duties and taxes are based on the customs value and the HS code of your products, not on their volume. CBM and weight mainly decide the freight cost, which is one part of your total landed cost.

When should I book a full container instead of LCL?

Many shippers start comparing prices once a shipment passes about 13–15 CBM, because a 20ft container can then cost about the same as LCL. Rates change by route and season, so ask for both quotes.

Can I combine cartons from several suppliers in China?

Yes. Cartons from different factories can be collected at one warehouse in China and shipped together, which usually lowers the cost per CBM. AsiaCommerce can coordinate this consolidation together with quality checks before loading.

Why is my chargeable weight higher than my actual weight?

Your cartons are large for their weight, so the carrier charges by volumetric weight. Smaller or better-filled cartons can reduce the bill.

Does the calculator store my data?

No. All calculations run in your browser and nothing is sent to us. Your numbers only reach AsiaCommerce if you choose to send them through WhatsApp or the request form.