A standard 20ft dry container (20GP, ISO code 22G1) measures about 5,898 × 2,352 × 2,393 mm inside, holds 33.2 m³ and carries a typical payload of 28,250 kg. The door opening is 2,340 × 2,280 mm, so anything taller than 2.28 m will not go in even though the interior is 2.39 m high. This guide collects the numbers that matter, two worked examples and the mistakes we see most often on shipments out of Indonesia.
20ft container dimensions
External dimensions are fixed by ISO 668; internal dimensions depend on how each manufacturer builds the box. Treat the figures below as typical values and always check them against the door markings and the CSC plate of the unit you actually receive.
| Parameter | Typical 20GP value |
|---|---|
| Inside length × width × height | 5,898 × 2,352 × 2,393 mm |
| Door opening (W × H) | 2,340 × 2,280 mm |
| Outside dimensions | 6,058 × 2,438 × 2,591 mm (20' × 8' × 8'6") |
| Floor area | 13.87 m² |
| Internal volume | 33.2 m³ |
| Tare (empty weight) | 2,230 kg |
| Maximum gross mass | 30,480 kg |
| Maximum payload | 28,250 kg |
| ISO size-type code | 22G1 |
Payload is simply maximum gross mass minus tare: 30,480 − 2,230 = 28,250 kg. Some newer boxes carry a higher rating, but never assume it; the binding number is the one painted on that unit. For every container type side by side, open Container Sizes.
Reading the door markings
The right-hand door normally shows the container number, the size-type code (for example 22G1) and three weights: MAX GROSS, TARE and NET or PAYLOAD, usually in both kg and lb. Many owners also print CU. CAP, the cubic capacity in m³ and ft³. The CSC plate on the door states the approved maximum gross mass, the allowable stacking load and the periodic examination details. If the door figures differ from your booking, the physical unit wins. Photograph these markings during stuffing; the photos help with VGM paperwork, claims and cross-checking the container number on your shipping documents.
Also be careful with data sources. Carrier and depot tables often round their figures to 33 m³ or 28 t. For a tight load plan, use the real unit's numbers, not the brochure numbers.
Why door height matters more than internal height
The 2,393 mm internal height only exists behind the door header. Forklifts, pallets and cargo all have to pass through a 2,280 mm opening. A 2.30 m machine or crate would fit inside on paper, yet it cannot be loaded. For cargo like that, look at the 40ft high cube or an open top container.
Payload versus road limits
The 20ft box is the usual choice for dense cargo: cement, ceramic tiles, bagged coffee, metals or paper. That is exactly where people get caught. The 28,250 kg payload is a structural limit of the container, not of the truck. On land, what counts is the vehicle's gross weight rating (JBB in Indonesia), the capacity of the container trailer and the road class under Law 22/2009.
The Stowage.id catalogue uses a default payload of 24,000 kg for a 20' trailer. If the container's gross mass (cargo plus the 2,230 kg tare) is capped at 24,000 kg, the cargo you can safely truck is only about 21,770 kg, well below 28,250 kg. Your trailer may differ; use the vehicle's KIR test book and registration, then check the combination with the ODOL Check.
The ship will also want a VGM, the verified gross mass required under SOLAS since 1 July 2016. A planner simulation helps you estimate weight, but it does not replace official weighing or operator approval. Our VGM and SOLAS guide covers the methods.
What fits in a 20ft container
Pallets
With a two-column mixed pattern (one column of pallets turned crosswise, one lengthwise), the theoretical single-layer capacity with zero clearance is:
| Pallet type | Base | One layer in 20GP |
|---|---|---|
| Indonesian/ISO standard | 1200 × 1000 mm | 9 |
| EUR/EPAL | 1200 × 800 mm | 11 |
| Asian | 1100 × 1100 mm | 10 |
| Container-optimised | 1140 × 1140 mm | 10 |
| North American | 48 × 40 in (1219 × 1016 mm) | 9 |
The 2,393 mm internal height allows two tiers of pallet loads around 1,150 mm tall each, as long as the bottom packaging is strong enough and the total weight stays within limits. The full method is in how many pallets fit in a container.
Cartons
For a single carton size in a single orientation, the theoretical counts are roughly:
| Carton size | Count in 20GP | Arrangement |
|---|---|---|
| 600 × 400 × 400 mm | 225 | 9 × 5 × 5 |
| 500 × 400 × 300 mm | 392 | 14 × 4 × 7 (turned to 400 × 500 × 300) |
| 450 × 350 × 300 mm | 570 | 19 × 6 × 5 (turned to 300 × 350 × 450) |
Mixing orientations often squeezes in a few more cartons, which is why we built the Cartons per Container calculator and wrote a guide to cartons per container.
Worked example
Case 1 — light cartons. A handicraft exporter ships 500 × 400 × 300 mm cartons at 18 kg gross each. Turned to 400 × 500 × 300 mm: 5,898 / 400 = 14 rows, 2,352 / 500 = 4 across, 2,393 / 300 = 7 high, so 14 × 4 × 7 = 392 cartons.
- Cargo volume: 392 × 0.06 m³ = 23.52 m³ (about 71% of the internal volume).
- Cargo weight: 392 × 18 kg = 7,056 kg, far below the payload.
- Conclusion: the box "cubes out" long before it "weighs out". The leftover space sits at the ends and the top; a mixed orientation can recover part of it.
Case 2 — dense cargo. A tile distributor loads 18 pallets of 1200 × 1000 mm, double-stacked, at 1,300 kg gross per pallet including the wooden pallet.
- Cargo weight: 18 × 1,300 = 23,400 kg, still under the 28,250 kg payload.
- Container gross mass: 23,400 + 2,230 = 25,630 kg.
- If your trailer is limited to 24,000 kg of container gross mass, this load is too heavy for the road even though the container itself is fine. Cut it to about 16 pallets or split it over two boxes.
Carton volume is explained step by step in how to calculate CBM, and you can run a quick check with the CBM Calculator.
Common mistakes
- Using internal height instead of door height. Anything over 2,280 mm will not go through.
- Treating payload as the truck limit. Road limits often bind first; see Indonesian truck sizes.
- Planning on the full 33.2 m³. For mixed cartons plan 80–90% and leave room for dunnage and securing.
- Piling weight at one end. Heavy cargo goes on the floor and is spread evenly; the centre of gravity should sit close to the middle of the length, roughly within ±0.3 m for a 20ft box.
- Forgetting pallet and securing weight. Eighteen wooden pallets add about 450 kg.
- Not inspecting the unit. Holes, a damaged floor or odours can get a food cargo rejected.
When a 20ft is the right box
Choose a 20GP for dense cargo that hits the weight limit quickly, for small volumes of roughly 15–28 m³, or for shipments you need to split across destinations. For light, bulky cargo a 40ft is almost always cheaper per cubic metre. Compare all three sizes in 20ft vs 40ft vs 40HC or directly in Container Compare.
Plan your load
Enter your cartons or pallets in the 3D load planner to see the arrangement, the remaining space and the estimated weight per container. The result is a simulation: official weighing, the VGM and the carrier's acceptance remain the final word.