How many cartons fit in a 20GP container?

▲ 19 votes 2 answers 383 views Asked 4 months ago answered

I know the internal dimensions of a 20GP are approximately 5.89 Ã— 2.35 Ã— 2.39 meters (L Ã— W Ã— H). But when I calculate the theoretical capacity (33.1 CBM), my actual loading always comes in lower.

For standard export cartons of 60 Ã— 40 Ã— 40 cm, how many should I expect to fit? And what's a realistic utilisation percentage I should plan for? Is there a standard loss factor for container loading calculations?

2 Answers

✓ Best Answer

Great practical question. The gap between theoretical capacity and actual load is very real and there are several factors at play.

Theoretical calculation for your carton:
Each carton: 0.60 Ã— 0.40 Ã— 0.40 = 0.096 CBM
20GP internal volume: 5.89 Ã— 2.35 Ã— 2.39 = 33.1 CBM
Theoretical cartons: 33.1 Ã· 0.096 = 344 cartons

Reality check â€” utilisation factors:

Carton-to-container dimension mismatch: Container internal dimensions (5.89 m) rarely divide evenly by carton dimensions. For 60 cm cartons on the 5.89 m length: 5.89 Ã· 0.60 = 9.8 â†’ you get 9 rows. Width 2.35 m Ã· 0.40 = 5.8 â†’ 5 columns. Height 2.39 m Ã· 0.40 = 5.97 â†’ 5 layers.

Actual fit per layer: 9 Ã— 5 = 45 cartons Ã— 5 layers high = 225 cartons at 0.40 m high. But you can stack 60 cm on its long axis: let me recalculate â€” if stacking with 40 cm height (box on flat): 5 layers. 225 Ã— 5 = 225 Ã— (2.39/0.40 = 5 layers) = 225 cartons.

Alternatively, rotating cartons or mixing orientations might give 230â€“250.

Dunnage and blocking: You need dunnage bags or wooden blocks to prevent cargo movement. This takes 1â€“3% of volume.

Weight limit: A 20GP has a payload of ~28 tonnes. If your cartons are heavy, you may hit the weight limit before filling the volume. 225 cartons Ã— (say) 20 kg each = 4,500 kg â€” well within limits for this scenario.

Practical utilisation rate: For standard rectangular cartons, expect 65â€“80% volumetric efficiency. Irregularly shaped or mixed cargo drops to 55â€“70%.

My estimate for your scenario: 220â€“240 cartons realistically, or roughly 68â€“72% utilisation.

John's calculation is solid. I want to add the weight/measure consideration that often catches people out.

20GP maximum payload: 21,727 kg (the ISO standard gross weight limit is 24,000 kg minus tare of ~2,200 kg). Some shipping lines have their own limits that are slightly different â€” check the specific carrier's container specifications.

For cartons of 60Ã—40Ã—40 cm, if each weighs 15 kg:

225 cartons Ã— 15 kg = 3,375 kg â€” far below weight limit, volume is the binding constraint

But if each weighs 80 kg (heavy machinery parts):

225 cartons Ã— 80 kg = 18,000 kg â€” approaching the weight limit
At 272 cartons Ã— 80 kg = 21,760 kg â€” you'd hit the weight limit at roughly 262 cartons before filling the container

Always check both CBM capacity AND weight capacity when planning a container load. The binding constraint (whichever you hit first) determines your maximum load.

For FCL planning, I recommend using CalculateCBM's container load calculator â€” it handles both volume and weight constraints simultaneously.