Calculate how many units fit in a container and optimize FCL vs LCL shipping decisions
Container load optimization calculates how many units of your cargo fit in different container sizes and identifies the limiting factor: volume or weight. This helps you choose between full and less-than-container loads.
FCL (full container load) is typically cost-effective for shipments over 15–25 CBM, depending on the lane and your freight forwarder. Below that, LCL (less-than-container) shared shipments are usually cheaper per CBM.
Choosing the wrong shipping method can add 20–50% to your freight costs. This calculator helps you find the optimal container size and loading strategy before you call your freight forwarder.
Learn the difference between FCL and LCL shipping, how to calculate CBM, and strategies to optimize container utilization for maximum savings.
Read the Guide →| Container Type | Internal Length | Internal Width | Internal Height | Volume (CBM) | Max Payload (kg) | Best For |
|---|---|---|---|---|---|---|
| 20' GP | 589 cm | 235 cm | 239 cm | 33.2 CBM | 21,727 kg | Dense/heavy cargo, small lots |
| 40' GP | 1,200 cm | 235 cm | 239 cm | 67.7 CBM | 26,680 kg | General cargo |
| 40' HC | 1,200 cm | 235 cm | 269 cm | 76.4 CBM | 26,460 kg | Light/bulky cargo, tall items |
| 20' Reefer | 529 cm | 229 cm | 222 cm | 26.9 CBM | 21,200 kg | Temperature-controlled |
| 40' HC Reefer | 1,162 cm | 229 cm | 259 cm | 67.3 CBM | 25,980 kg | Large temp-controlled lots |
Common questions about container specifications and ocean freight
A standard 20-foot GP (General Purpose) container has an internal volume of 33.2 CBM and internal dimensions of approximately 589 cm × 235 cm × 239 cm (L×W×H). The maximum payload is 21,727 kg (47,900 lbs). Note that volume and weight limits are independent constraints — dense cargo (like steel) hits the weight limit before filling the volume.
A 40-foot High Cube container has an internal volume of 76.4 CBM and internal dimensions of approximately 1,200 cm × 235 cm × 269 cm (L×W×H). The extra 30 cm of height compared to a 40-foot GP container adds about 8 CBM of usable space. Maximum payload is 26,460 kg. HC containers are preferred for light, bulky cargo like furniture, apparel, and electronics.
The 40-foot GP (General Purpose) and HC (High Cube) containers have identical length and width. The difference is internal height: GP is 239 cm (7.84 ft) tall internally; HC is 269 cm (8.83 ft) tall — approximately 30 cm (1 foot) taller. The HC provides 76.4 CBM vs 67.7 CBM for the GP. HC containers cost approximately $50–$150 more per booking but are often worth it for high-cube cargo.
LCL (Less-than-Container-Load) is typically more economical when your cargo is under 15 CBM. Between 15–25 CBM, compare LCL rates (typically $65–$85/CBM base) vs FCL rates for a 20-foot container. Above 25 CBM, a 20-foot FCL container is almost always cheaper. FCL also offers faster transit, lower damage risk, and no co-mingling with other shippers' cargo.
Standard container payload limits: 20-foot GP = 21,727 kg (47,900 lbs), 40-foot GP = 26,680 kg (58,820 lbs), 40-foot HC = 26,460 kg (58,330 lbs). Note that these are payload limits — maximum cargo weight before the container itself becomes overweight on road. US road weight limits (80,000 lbs gross for a standard 5-axle truck) further limit practical payload to approximately 20,000–24,000 kg for a 20-foot container on a chassis.
To calculate container loading: (1) Convert your cargo dimensions to meters. (2) Calculate volume per unit (L × W × H). (3) Divide container volume by unit volume to get volume-limited units. (4) Divide max payload by unit weight for weight-limited units. (5) The actual number that fits is the lower of these two values. This calculator automates that math and shows you which constraint — volume or weight — is the binding factor.
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