Refrigerated
Reefer container loading calculator
A refrigerated box is smaller inside than its dry equivalent and stricter about how it is loaded. Internal dimensions to the load line, the pallet counts, the airflow rules that decide whether the cargo arrives cold, and a 3D plan — the planner below opens on a 20 ft reefer.
Free, and you can run one calculation before signing in at all.
The short answer
10 euro pallets in a 20 ft reefer. 23 in a 40 ft reefer. Payload up to about 29 tonnes.
Single tier, no overhang, cargo below the load line.
The machinery, the insulation and the T-section floor all take space, so a 20 ft reefer is about 5.44 m long inside against 5.90 for a dry box, and a 40 ft reefer 11.56 against 12.03. That costs a pallet in each. What a reefer gains is weight: the rating is higher, so dense chilled cargo — meat, juice, seafood — often carries more tonnes in a reefer than in a dry box of the same size.
Reefer dimensions
The refrigerated boxes in common use, with internal dimensions quoted to the load line, one-tier pallet counts, payload and volume.
| Container | Internal L × W × H | Pallets, one tier (euro · industrial) | Payload · volume |
|---|---|---|---|
| 20 ft reefer | 5.44 × 2.29 × 2.27 m | 10 · 9 | ~27,500 kg · 28 m³ |
| 40 ft reefer | 11.56 × 2.29 × 2.25 m | 23 · 20 | ~29,000 kg · 59 m³ |
| 40 ft high cube reefer | 11.56 × 2.29 × 2.55 m | 23 · 20 | ~29,000 kg · 67 m³ |
| 45 ft high cube reefer | 13.10 × 2.29 × 2.55 m | 26 · 23 | ~29,000 kg · 76 m³ |
Nominal figures, and reefers vary more than dry boxes by make and by generation. Internal height is measured to the red load line, not the roof; cargo above it blocks the return air and the box does not hold temperature.
Pack a reefer
The planner is already set to a 20 ft reefer. Enter your pallets or cartons and it places every piece within the box; keep the load below the line and off the doors so the air path stays open.
This is the planner itself, not a demo. Enter your own cargo and it packs it — the figures above are the starting point, not the answer for your load.
What changes the answer
Four things that make a reefer load different from the same cargo in a dry container.
- The load line and the air path
- A reefer's usable height stops at the red line, not the roof, and the T-floor and the door end must stay open so cold air circulates under, over and back. A box loaded to the ceiling is a box that arrives warm at the far end.
- Weight before space
- Dense cargo hits the payload limit long before it fills the floor. A 20 ft container holds about 28 tonnes and 33 m³ — anything above roughly 850 kg per cubic metre runs out of weight first, and the pallet count stops mattering.
- What may sit on what
- Double-stacking doubles a count only if the lower tier can carry the upper one and the total clears the roof. Fragile, non-tiltable and crush-limited items break that arithmetic, and they are the norm rather than the exception.
- The door, not the box
- A standard container door is about 2.34 m wide and 2.28 m high — narrower and lower than the 2.35 × 2.39 m inside. Anything that fits the box but not the opening does not go in, and a high cube's taller door is often its real advantage.
Questions
How many pallets fit in a 40 ft reefer?
23 euro pallets or 20 industrial on a single tier, in either the standard or the high cube reefer — two fewer than a dry 40 ft, because the box is 47 cm shorter inside.
Why is a reefer smaller inside than a dry container?
Insulated walls, the refrigeration unit in the front wall and a T-floor for air return all take space from the same external envelope. A 20 ft reefer loses about 46 cm of length and 6 cm of width; a 40 ft loses about 47 cm of length.
What is the load line in a reefer?
A red line on the walls marking the maximum height cargo may be stacked to. Air supplied under the T-floor returns over the top of the load; cargo above the line blocks that path, and the box stops holding temperature at the far end.
Can I load a reefer solid to the doors?
No. Leave the T-floor open for airflow, keep cargo clear of the door panels, and do not block the return grille at the machinery end. The planner keeps the box dimensions honest; the airflow clearances are yours to keep.