What is a loading metre (LDM) and how is it calculated?

A loading metre (LDM) is the unit that shows how many metres of trailer floor a load takes up. In part load and groupage freight, the price usually rests not on weight alone but on how much floor space the goods occupy. Since trailer width is fixed, space is expressed as length.

The basic logic

For LDM the trailer width is taken as roughly 2.4 metres. A strip of floor 1 metre long and 2.4 metres wide is 1 LDM. The formula is:

LDM = length (m) x width (m) / 2.4

This is a working convention. A standard curtainsider has an internal width of about 2.45 metres and an internal length of about 13.6 metres, so a fully loaded trailer is at most 13.6 LDM. Exact figures vary by a few centimetres from vehicle to vehicle.

LDM per pallet

• EUR pallet (120 x 80 cm): three pallets fit across the width and each row takes 1.2 metres. That is 1.2 / 3 = 0.4 LDM per pallet. Same result as 0.96 / 2.4 = 0.4.
• Industrial pallet (120 x 100 cm): two fit across (2 x 1.2 = 2.4) and each row takes 1.0 metre. That is 1.0 / 2 = 0.5 LDM per pallet.
• A full-width row: three EUR pallets in one row make 1.2 LDM, and that 1.2 metres of floor cannot be shared with other cargo.

Ten EUR pallets make 4 LDM. Ten industrial pallets make 5 LDM.

Why real life rarely matches the sum

• Non-stackable goods: a pallet that cannot be stacked takes its full floor area however tall it is. Stackable goods bring the LDM down, so the listing should say whether they are stackable.
• Overhanging or irregular cargo: goods larger than the pallet are rounded up, because the space beside them cannot be used.
• Fit: if pallets do not sit tightly side by side, floor space is lost. In practice 33 EUR pallets fit a standard trailer; some layouts reach 34.

How it relates to weight

Many carriers convert LDM to weight on part loads and quote on whichever is greater. A common continental convention is about 1.85 tonnes of chargeable weight per LDM, but that is a commercial habit and not a law; the UK, the Nordics and some companies use other values. Ask what your quote or contract uses.

What to put in a listing

1. Number of pallets and pallet type (EUR or industrial).
2. Dimensions (length, width, height) and gross weight of each pallet.
3. Stackable or not.
4. Total LDM, with your calculation in one sentence so the carrier can check it.

On part loads the LDM figure is essential so the carrier can reserve space at a glance. Short definitions of the terms are in the Freight Glossary; for how part loads work, see the article on part load and groupage.