Loading meters (LDM) explained: how to measure your shipment for an accurate groupage quote

A loading metre, abbreviated LDM (from the French 'mètre de chargement') or sometimes LM, is one linear metre of trailer floor measured along the length of the deck, across the full usable width of the trailer. A standard European curtainsider is about 2.4 m wide internally, so one LDM is roughly one metre long by 2.4 m wide — a strip of floor of about 2.4 square metres. It is a measure of floor space blocked, not of volume or weight.

The reason the LDM exists is simple: in a partial load, the constraint that matters is how much of the deck length your goods take up, because that is the length no other shipper can use. A standard 13.6 m curtainsider trailer therefore holds about 13.6 LDM of floor. When you book groupage, you are reserving some number of those 13.6 metres, and the price follows from how many you block.

Height barely enters the calculation for floor-standing goods, because a trailer that is full along its length is sold out regardless of how much headroom is left above the pallets. That is also why stackability matters so much, and why it gets its own section below.

For floor-standing, non-stackable pallets the formula is short. Take the footprint of each pallet — its length multiplied by its width, in metres — multiply by the number of pallets to get the total floor area, then divide by the trailer width of 2.4 m. In one line: LDM = (pallet length × pallet width × number of pallets) ÷ 2.4.

The division by 2.4 is the whole trick. You are converting square metres of floor into linear metres of deck, because the deck is sold by the metre and is always 2.4 m wide. A footprint of 2.4 m² is exactly one loading metre; half that footprint is half a metre, and so on.

This works because a non-stackable pallet blocks its entire footprint from front to back — nothing can sit on top of it, so the floor under it is committed for the length of the trip. The footprint is what you pay for. For stackable goods the picture changes, which we cover shortly.

The single biggest lever on your LDM is whether your goods are stackable. A pallet marked stackable can have another pallet placed on top of it, so two stackable pallets share one footprint of floor — which roughly halves the loading metres each one contributes. Five stackable EUR pallets that would be 2.0 LDM on the floor become about 1.0 LDM stacked two-high, because the deck space is shared.

A non-stackable pallet does the opposite: it blocks its full footprint and the headroom above it goes to waste, because nothing can be loaded on top. That waste is real space the carrier cannot sell to anyone else, which is exactly why it is built into your price. Fragile goods, top-heavy machinery, open-topped containers and anything bearing a 'do not stack' cone are all non-stackable by necessity.

Because stackability can halve your loading metres — and therefore your groupage price — it is worth getting right and declaring honestly up front. Our companion guide on stackable vs non-stackable pallets covers how to qualify, label and palletise for stacking, and the cost difference it makes.

Groupage pricing rests on one principle: you pay for the most constraining resource your load uses on the trailer, whether that is weight or floor space. Carriers express this by comparing your actual gross weight against an LDM-equivalent weight and charging on the greater of the two. A dense, heavy load is billed on its real weight; a light, bulky load is billed on the space it occupies.

To make the comparison, each loading metre is assigned an indicative weight equivalent. A common figure is roughly 1 LDM ≈ 1,750–1,850 kg — that is, occupying one metre of deck is treated as equivalent to carrying around 1.8 tonnes, because that is about what a metre of trailer could otherwise earn in dense freight. Treat this as indicative only: the exact conversion varies by carrier, lane and trailer type, and the binding figure is always the one in your written quote.

Run the comparison on a worked case. Suppose you have five non-stackable EUR pallets weighing 600 kg in total. The floor space is 2.0 LDM, and at an indicative 1,800 kg per LDM that is an LDM-equivalent weight of about 3,600 kg. Because 3,600 kg is far above the 600 kg on the scale, the load is chargeable as roughly 3,600 kg — you are paying for the space you block, not the weight you ship. Our chargeable-weight guide works the same logic from the volumetric angle.

This is precisely why light-but-bulky and tall, non-stackable freight is called 'voluminous' and priced on LDM rather than weight. Insulation, foam, packaging, furniture, plastics, empty containers and a lot of e-commerce freight all weigh far less than 1,800 kg per metre of deck, so the loading metres win the comparison and set the bill.

Our budget calculator and written quote both take linear metres plus weight as their core inputs, then apply the greater-of rule above to land on a chargeable basis for your lane. If you feed in accurate loading metres and an honest stackable or non-stackable flag, the indicative number you see and the firm number we return line up — there is nothing left to discover when the freight reaches the hub.

Getting the LDM right up front is mostly about avoiding a re-rate. If a shipment is quoted as stackable but arrives marked 'do not stack', or if the loaded footprint is bigger than declared because of overhang, the loading metres rise and the price has to be corrected at the hub. Declaring the real footprint and the real stackability the first time keeps the written quote firm.

Our scheduled groupage runs three times a week — Monday, Wednesday and Friday — out of the Castellar del Vallès hub near Barcelona, and a written quote is typically ready in about 15 to 20 minutes and valid for 24 hours. Loading metres and weight are what the quote is built on, so they are the two numbers worth measuring carefully before you submit.

Floor-standing (non-stackable) rules of thumb: one EUR pallet (1.2 × 0.8) ≈ 0.4 LDM, so two EUR pallets ≈ 0.8 LDM loaded two-abreast across the 2.4 m width; one industrial pallet (1.2 × 1.0) = 0.5 LDM, so two industrial pallets = 1.0 LDM. A standard 13.6 m curtainsider holds about 13.6 LDM in total.

For stackable goods, halve those figures: two stackable EUR pallets share one footprint, so five stackable EUR pallets are about 1.0 LDM rather than 2.0. To check whether weight or space governs your price, compare your gross weight against your LDM × an indicative 1,750–1,850 kg per metre, and expect to be billed on the greater of the two.

Before you book: measure the real loaded footprint including any overhang, confirm whether each pallet is genuinely stackable, work out the loading metres with LDM = (length × width × pallets) ÷ 2.4, then enter the linear metres and weight into the budget calculator and submit the form for a firm written quote. The calculator figures are indicative; the binding number is the one in your written quote.