1. Maximize Cube Utilization, Not Just Weight
Ocean freight is charged per container regardless of weight, up to the container's maximum payload (published: 62,016 lb for a 20', 63,383 lb for a 40'). Never ship air. A half-empty container costs the same as a full one. Target 85%+ cube utilization. Use this calculator's cargo list to see the space and weight left.
2. Choose 40' HC for Tall or Stackable Cargo
40' High Cube provides about 13% more volume than a 40' GP (76 m³ vs 67 m³). The extra 11.9 inches of inside height (106.1" vs 94.2") allows double-stacking of standard 48-inch pallets (96" stacked height). For cargo over 7.5 feet tall, 40' HC is your only option. Ask your forwarder for the price difference; it can be worth it if it saves you a second container.
3. Load Heavy Items at Bottom and Near Container Doors
Container doors are at one end only. Weight distribution matters for safe loading/unloading. Place heavy items (machinery, metal parts, dense cargo) at the bottom and toward the door-end (front). Lighter items go on top and toward the rear. Top-heavy or rear-heavy loads risk tipping when forklifts remove cargo. This also prevents cargo shift during ocean transit, which can cause severe damage or even container collapse in rough seas.
4. Secure Cargo with Proper Dunnage and Restraints
Ocean containers experience significant movement during transit—rolling, pitching, and yawing in rough seas. Unsecured cargo shifts, causing damage to goods and potentially damaging the container itself. Use wood dunnage between layers, load bars at the rear of cargo, inflatable airbags to fill voids, and shrink wrap for pallet stability. Securing materials usually cost far less than a damaged-goods claim.
5. Account for Door-End Taper and Wall Corrugation
Containers aren't perfectly rectangular inside. The door-end tapers by 2-3 inches over the last 12-18 inches of length. Corrugated steel walls reduce usable width by 1-2 inches per side. The shipping lines publish nominal inside sizes, and individual containers vary slightly. This planner uses the more conservative published inside sizes but does not subtract anything else, so leave a little room.
6. Use Floor-Loading for Small, Lightweight Items
If shipping cartons under 50 lbs each (e.g., apparel, consumer electronics, small goods), consider floor-loading (hand-stacking) instead of palletizing. Pallets use vertical space—a 5-inch pallet base reduces usable height from 94.2" to 89.2" in a standard container. Floor-loading usually fills more of the container's volume than palletized loading. Trade-off: more labor to load and unload, so compare that labor with the freight cost per container.
7. Consider LCL for Partial Loads (Under 15 Cubic Meters)
Shipping less than 10 pallets or 15 cubic meters? Consider LCL (Less than Container Load) where your cargo shares a container with others. You pay only for space used, charged per cubic meter at a rate that depends on the route. For small volumes LCL is usually cheaper than a full 20' container; as the volume grows, FCL (Full Container Load) becomes more economical. Use this calculator to estimate your cubic meters, then compare LCL vs FCL quotes.
8. Always Verify Tare Weight + Cargo Weight < Max Gross Weight
The container's rated maximum is on its CSC plate, together with its tare (empty) weight. Published figures: 20' tare 5,181 lb, max payload 62,016 lb (28,130 kg), max gross 67,197 lb; 40' tare 8,267 lb, max payload 63,383 lb (28,750 kg), max gross 71,650 lb (32,500 kg); 40' HC tare 8,598 lb, max payload 63,052 lb. Road and rail weight limits vary by country and are often lower, so check with your trucker. Weigh your cargo before loading.