How to calculate LDM
Loading metres decide what a part load costs, and most of the arguments about them come from people using the same word for different things. Here is what an LDM actually measures, the formula, and the three places it quietly misleads you.
What a loading metre actually is
A loading metre is one metre of trailer floor taken across its full width. By convention across Europe that width is fixed at 2.40 m, so one LDM is 2.4 m² of deck — even though most trailers are really 2.45 or 2.48 m inside.
That gap between the convention and the actual trailer is deliberate. If every forwarder measured against their own equipment, no two quotes would ever compare. Fixing the width means an LDM is the same unit in Riga as it is in Rotterdam, and a rate per LDM means something.
A standard 13.6 m tautliner is therefore 13.6 loading metres. When you buy 6 LDM on a groupage truck, you are buying 6 metres of that floor from side to side, and nobody else can use them.
The formula
The order matters less than the idea: work out how much floor one unit eats, multiply by how many you have, then divide by stacking. Everything else is arithmetic.
A EUR pallet is 1.20 × 0.80 m. One pallet: 1.20 × 0.80 ÷ 2.4 = 0.4 LDM.
Eighteen of them, not stacked: 0.4 × 18 = 7.2 LDM.
If they stack two high: 7.2 ÷ 2 = 3.6 LDM. Same goods, half the invoice line.
Try it on your own numbers
Notice what the formula does not ask about: height, weight, or what is on the pallet. It is a floor-space calculation and nothing else. That is its strength and, as you will see below, its blind spot.
What stacking does to the number
Stacking is the single biggest lever on a part load. A second layer halves the loading metres, and the loading metres are what you are paying for. Nothing else you can do to a shipment moves the price that far.
It only works if two things are true: the goods on the bottom can carry the weight of the goods on top, and the shipper agrees. A crushed bottom layer costs far more than the metres you saved, so a do-not-stack label is not a suggestion.
Height is the limit. Two pallets at 1.20 m each need 2.40 m of clear height, which a standard tautliner at roughly 2.70 m has. Two at 1.45 m need 2.90 m, and now you are booking a Mega.
What each pallet type costs you
The numbers below assume the pallet is loaded in whatever orientation wastes the least floor, which is what any sensible loader does.
| Pallet | Size | LDM each | In a 13.6 m trailer |
|---|---|---|---|
| EUR / EPAL | 120 × 80 cm | 0.40 | 33–34 |
| Industrial / FIN | 120 × 100 cm | 0.50 | 26 |
| Half EUR | 60 × 80 cm | 0.20 | 66 |
| Quarter EUR | 60 × 40 cm | 0.10 | 132 |
| UK standard | 120 × 100 cm | 0.50 | 26 |
The 33-versus-34 question for EUR pallets comes up constantly. Three across in eleven rows gives 33. Turn them all and put two across in seventeen rows and you get 34 — but every pallet has to face the same way, and a forklift driver working at speed will not do that unless you ask.
Mixed loads
With several sizes on one truck, calculate each type separately and add the results. The catch is that real loading happens in whole rows: if you have seven EUR pallets and the row takes three, you use three rows, not 2.33. The last row is paid for whether you fill it or not.
This is why the formula usually understates a mixed load slightly, and why a plan drawn to scale beats arithmetic. Our load planner lays out mixed cargo row by row and shows what the deck really looks like.
Three places the formula lies to you
When the weight runs out first
A 13.6 m trailer carries about 24 tonnes. Load 33 pallets of tiles at 900 kg and you are at 29.7 t — over the limit at 13.2 LDM, which the formula happily reports as fitting. Dense cargo hits the axle before it hits the headboard, and no loading-metre number will warn you.
When the row does not fill
A single pallet standing alone in a row burns the whole 2.40 m width. Two pallets in a row of three still cost you the full row. Half-empty rows are what quietly destroy the economics of a part load, and they never appear in a per-pallet calculation.
When the cargo cannot be turned
The formula assumes the best orientation. Long items that must stay lengthwise, cargo with a fixed forklift entry side, or anything over 2.40 m in one dimension breaks that assumption immediately. A 3 m pipe does not occupy 3 m ÷ 2.4 of anything useful — it occupies a lane of the trailer for its whole length.
Loading metres tell you what the floor costs. They tell you nothing about weight, height or whether the thing physically goes in. Check all four before you quote, because the carrier will check them at the ramp.
Converting between LDM, pallets and cubic metres
| Loading metres | EUR pallets | Volume at 2.70 m | Share of a 13.6 m trailer |
|---|---|---|---|
| 1.2 | 3 | ~7.8 m³ | 9 % |
| 2.4 | 6 | ~15.6 m³ | 18 % |
| 4.8 | 12 | ~31 m³ | 35 % |
| 7.2 | 18 | ~47 m³ | 53 % |
| 13.2 | 33 | ~86 m³ | 97 % |
Volume assumes goods stacked to the full internal height, which almost never happens. Treat the cubic metres as a ceiling, not a measurement.
Questions people actually ask
Is a loading metre the same as a square metre?
No. A loading metre is 2.4 m^2, because it is one metre of length across the standard 2.40 m width. Quoting in square metres and in loading metres will give you two different numbers for the same pallets.
How many loading metres is one EUR pallet?
0.4 LDM. That is 1.20 x 0.80 divided by 2.4. A half pallet is 0.2 and an industrial 120 x 100 pallet is 0.5.
How do I convert LDM to cubic metres?
Multiply by 2.4 for the floor area, then by the height your goods actually reach. One LDM of cargo stacked 2.0 m high is 4.8 m^3. Never use the trailer's full internal height unless the load really goes that high.
Does the carrier charge for the metres I use or the metres I block?
The metres you block. If your pallets sit alone in their rows, the rest of the row cannot be sold to anyone else and you pay for it. This is why turning cargo so it fills a row completely is worth real money.
Why do some calculators say 13.6 LDM and others 13.2?
13.6 is the trailer. 13.2 is what 33 EUR pallets occupy when loaded three across in eleven rows. The 40 cm difference is real deck that a standard pallet layout cannot use.
Does LDM apply to a full truck load?
Not usefully. On an FTL you pay for the vehicle, so the loading metres are fixed at whatever the trailer is. LDM only earns its keep on part loads and groupage, where it decides how the cost is split.