The load chart (capacity plate) shows how much the truck may actually lift at a given load centre and lift height — not just the nominal figure. Here's how to read off the nominal capacity, load centre and lift height, and why the capacity drops.
Introduction
The truck's nominal capacity (e.g. »1,600 kg«) applies only at a specific standard load centre and a limited lift height. The actual permitted load for your particular situation must be read off the load chart — it is the truck's own definitive answer and can never be replaced by a generic table.
What is the load centre?
The load centre is the horizontal distance from the vertical front face of the forks to the load's centre of gravity. The nominal capacity is stated at a standard load centre, which depends on the size of the truck.
| Forklift capacity | Standard load centre |
|---|---|
| 0–1,000 kg | 400 mm |
| 1,001–5,000 kg | 500 mm (the typical reference point) |
| 5,001–10,000 kg | 600 mm |
Why capacity drops
Both an increased load centre AND an increased lift height reduce the permissible load. Toyota gives a concrete example for a truck rated at a nominal 1,600 kg at a 500 mm load centre:
| Load centre \ Lift height | 3000 mm | 5000 mm | 7000 mm |
|---|---|---|---|
| 500 mm | 1,600 kg | 1,600 kg | 750 kg |
| 1000 mm | 990 kg | 930 kg | 460 kg |
At a 1000 mm load centre and 7000 mm height, the capacity drops to 460 kg — about 71 % below nominal. The figures apply ONLY to this one forklift and must never be generalised.
The type plate field by field
The load chart rarely stands alone. On the same capacity/type plate (often called a 'data plate') you find the information that binds the figures to this specific truck. DS/EN ISO 3691-1 requires that the truck is permanently and legibly marked with this data — if the plate is illegible or missing, the truck must not really be used until the marking is restored. Review the fields each time you sit in a truck you don't know.
| Field on the sign | What it means — and why it is important |
|---|---|
| Manufacturer, model and serial no. | Uniquely identifies the truck; serial no. is used in inspections, spare parts and accident investigation. |
| Year of construction | Age matters for wear, standard basis and spare parts. |
| Truck's own weight (service weight) | Truck + full battery/tank without load. Determine together with the load the total centre of gravity and the load on the ground, ramps and floor decks. |
| Nominal capacity | The maximum load at standard load centre and limited lifting height — the starting point, not the answer. |
| Standard load centre | That load centre (e.g. 500 mm) to which the nominal capacity applies. |
| Max. lifting height | The physical tip height of the mast; capacity is often lower at the top. |
| Mast type | Duplex/triplex/special — determines free space and free height requirement. |
| Tyre type | Air, super-elastic or solid tyres; affect stability, substrate and indoor use. |
| Battery weight (min./max.) | On electrically powered trucks, the battery is part of the counterweight — see below. |
Battery weight is part of the counterweight
In an electrically powered counterweight truck, the battery sits low at the rear and forms part of the counterweight. For this reason, the nameplate specifies a permitted minimum and maximum battery weight. If you fit too light a battery (for example a smaller replacement battery), the counterweight is reduced — and with it the stability and permitted load — even though the load diagram looks unchanged. Always check that the battery weight lies within the nameplate interval; it is a typical, overlooked source of error after battery replacement.
Accessories have their own diagram
The moment you attach an attachment — side shifter, clamp (for example for paper rolls or white goods), rotator, bale grab or fork extensions — the truck's original capacity plate no longer applies. The combination truck + attachment has ITS OWN diagram (a rated capacity), because the attachment does three things at once:
- 01Adds its own dead weight in front of the front axle — it counts as part of the load.
- 02Moves the load's centre of gravity further forward (larger load centre) because the accessories build in depth.
- 03Can raise the centre of gravity and change visibility — both affect stability and safe driving.
Fork attachment and fork technical characteristics are standardised in DS/EN ISO 2328 and DS/EN ISO 2330 so accessories fit on the truck's slide — but fit is not the same as capacity. All lifting attachments must be CE-marked and have their own capacity plate for the combination. Never make up a capacity: read it from the attachment's/combination's plate.
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