Shipping Container Load Calculator
Calculate how many items fit inside a 20-ft, 40-ft, or 40-ft high-cube shipping container based on item dimensions and weight. Essential for import/export planning and ocean freight cost estimation.
About this calculator
Container capacity is constrained by two independent limits: volume and maximum payload weight. For each container type, the usable internal dimensions (in inches) are fixed: a 20-ft container offers roughly 230 × 92 × 95 inches of internal space with a 33,440 lb payload limit; a standard 40-ft offers 468 × 92 × 95 inches with 59,040 lbs; and a 40-ft high-cube offers 468 × 92 × 108 inches with the same weight limit. The number of items that fit is: count = min(⌊container volume / item volume⌋, ⌊max payload / item weight⌋). This assumes perfect packing efficiency with no wasted space — real-world loading is typically 70–85% of the theoretical maximum due to stacking constraints and irregular shapes.
How to use
You want to load boxes measuring 20 × 15 × 12 inches, each weighing 40 lbs, into a standard 40-ft container (468 × 92 × 95 in, max payload 59,040 lbs). Step 1 — volume limit: (468 × 92 × 95) / (20 × 15 × 12) = 4,094,640 / 3,600 ≈ 1,137 boxes. Step 2 — weight limit: 59,040 / 40 = 1,476 boxes. Step 3 — binding constraint: min(1,137, 1,476) = 1,137 boxes. Volume runs out first. Apply an 80% real-world efficiency factor: 1,137 × 0.8 ≈ 909 boxes is a practical loading estimate.
Frequently asked questions
How many boxes can fit in a 20-foot shipping container?
A standard 20-foot container has internal dimensions of approximately 230 × 92 × 95 inches (about 1,172 cubic feet) and a maximum payload of around 33,440 lbs. The theoretical number of boxes depends on individual box volume and weight. For example, standard 12 × 10 × 10 inch boxes weigh about 10 lbs each — the volume limit allows roughly 1,690 boxes while the weight limit allows 3,344, so volume is the constraint at about 1,690 units. In practice, expect 75–85% of the theoretical maximum due to stacking patterns and loading inefficiencies.
What is the difference between a standard 40-ft and a 40-ft high-cube shipping container?
A standard 40-ft container has an internal height of approximately 95 inches (about 7 ft 10 in), while a 40-ft high-cube container is roughly 13 inches taller at about 108 inches (9 ft). This extra height adds approximately 480 cubic feet of usable volume, which can be significant when shipping tall or voluminous cargo. High-cube containers are commonly used for lightweight but bulky goods such as furniture, mattresses, and electronics. They typically cost only slightly more to rent or ship than standard containers, making them excellent value when volume is the binding constraint.
How do I calculate container utilization and why does it matter for import costs?
Container utilization is the ratio of the volume actually occupied by cargo to the total internal volume of the container, expressed as a percentage. High utilization (above 80%) means you are maximizing the fixed ocean freight cost spread across more units, reducing the per-unit shipping cost. Low utilization below 50% may mean a smaller container or LCL (less-than-container-load) consolidation is more economical. To maximize utilization, use uniform carton sizes, stack cartons to the container ceiling, and plan loading sequences using a container loading calculator or 3D load planning software.