Container Loading Calculator — Cartons, Units and Real MOQ

For fans, motors and packaged units, ocean freight is charged on the space the goods take up, not on what they weigh. This works out what actually fits — and the order size that stops you paying to ship air.

A planning estimate based on the best single stacking orientation. Real stow depends on pallets, dunnage and the loader, and can differ either way. Confirm the figure with your forwarder before you commit to a quantity.

Why this decides your order size, not the supplier’s MOQ

A supplier’s stated minimum is a production constraint. The number that actually governs a first order is the one that fills a container, because ocean freight is billed per container, not per carton. Order 60% of a container and you have paid full freight on the empty 40%; that cost lands on your unit price just as surely as the factory price does. Where the supplier’s MOQ sits below a container load, the container is the real minimum worth placing.

Volume-limited is the normal case in HVACR

Fans, fan coils, air handling sections and duct components are light for their size, so they run out of space long before they run out of payload. A 40 HQ full of axial fans often ships at under a third of its allowed weight. That is why carton design is worth arguing about: a supplier who nests impellers or ships motors separately from housings can put substantially more product in the same box, and the saving is entirely yours.

Ask for packed dimensions, not product dimensions

Quotations routinely give the product size and omit the carton. The difference is not trivial — protective packing on a 500 mm fan can add 80 mm on every face, which is roughly a third more volume and a third more freight. Always ask for the outer carton length, width and height, the gross weight and the units per carton, and put those three in the purchase order alongside the price.

The weight cap is often lower than the container’s

A 40 HQ is rated for around 28 tonnes, but the road leg at either end is frequently capped well below that — commonly 21 to 24 tonnes depending on the country and the chassis. If the load is weight-limited, check the destination road limit before planning to the container rating, because a container that cannot legally leave the port has to be stripped and re-loaded at your cost.

Link to or cite this tool

If this calculator is useful in a specification, tender document or forum answer, please link to it rather than copying the figures — the assumptions behind it are stated above and may be updated.

https://www.hvacrnexus.com/tools/container-loading-calculator/

Working out the fan side

Once the refrigeration duty is fixed, the evaporator fans and any condenser fans are a separate calculation. Longwell publishes a set of fan-side tools — airflow, static pressure, fan laws and motor sizing — at longwellfans.com.

Equipment this calculation points to

Questions about this calculation

How many cartons fit in a 40 HQ container?
It depends entirely on carton size. A 40 HQ has roughly 76 CBM of internal space (12.03 × 2.35 × 2.69 m) and about 28 tonnes of payload. Enter your packed carton dimensions and gross weight above and the calculator works out how many fit in the best stacking orientation, and whether space or weight runs out first.
Should I ship LCL or wait until I have a full container?
LCL is charged on volume with a minimum, and it adds handling, consolidation and usually a longer transit. As a rough guide, once a shipment passes roughly a third of a container it is worth pricing both ways, and past half a container FCL usually wins outright. The calculator gives you the full-container quantity so you know what you are comparing against.
Why is my freight cost so high when the goods are light?
Because ocean freight prices space, not weight. Ventilation equipment is bulky and light, so a container fills up long before it reaches its weight limit — you are paying to move air inside the cartons. The fix is on the packing side: knocked-down supply, nested components, or a tighter carton.
What is chargeable weight and does it apply here?
For air freight and courier, yes: the carrier charges on volumetric weight (typically length × width × height in cm divided by 6000) whenever that exceeds actual weight. For full-container ocean freight it does not apply — you pay for the box. This calculator covers the container case.

Send us the duty and we will quote matched equipment

Give us the figure this calculator produced, your room temperature and your location — we will come back with condensing unit and evaporator options, price and lead time, usually within one working day.