A capacity is a weight and a distance, together
Nothing on a forklift data plate says "5,000 lb". It says 5,000 lb at 24 in, and those two numbers are a single fact: a moment of 120,000 lb-in. Move the load out and the same moment allows less weight; bring it in and it allows more. The distance is measured horizontally from the front face of the forks to the centre of gravity of the load, which for an evenly packed load is half its depth.
That is why a load that is deep rather than heavy is the one that catches people out. A 4 ft deep pallet has a 24 in load centre and matches the plate exactly. Make it 5 ft deep at the same weight and the centre goes to 30 in, and the moment goes up 25 percent with nothing added.
The defaults, in the plate's own units
3,000 lb at a 30 in load centre is 90,000 lb-in. Expressed at the plate's 24 in that is the equivalent of 3,750 lb — 750 lb more than the load actually weighs, and that 750 lb is entirely the extra 6 in. The plate itself describes 120,000 lb-in. The two numbers are now in the same units and comparing them is the operator's job, not this page's.
The table on the page runs the same weight out to 60 in of load centre, where 3,000 lb is the equivalent of 7,500 lb at plate distance. That is a load which weighs less than the plate and asks half again as much of the truck.
Half the depth is an assumption, not a measurement
The load centre is only half the depth when the load is packed evenly. A crate with a motor bolted at one end, a pallet stacked heavy at the back, a coil sitting off centre, a bundle that overhangs the fork tips — all of them have a centre of gravity somewhere the outside of the load gives no clue about. The offset field on the page exists because that is a judgement to make deliberately rather than a number to assume.
The axles are the actual mechanism
Underneath the moment arithmetic is a see-saw. The front axle is the pivot, the truck's own weight behind it holds the back down, and the load ahead of it lifts. Feed in the service weight, the wheelbase and the truck's centre of gravity from the spec sheet and the page works out what is left on the steer axle. Watching that number fall as the load centre grows is the clearest picture of why load centre matters at all.
It is a static sum, and it deserves to be read as one. It has a level floor, a vertical mast and nothing moving. Forward tilt, braking, a ramp, a pothole and turning with a raised load all take from it. Real trucks are rated a long way inside the point where that arithmetic reaches zero, and the plate is the number that governs.
Load centre is one variable among several
Lift height, mast type, fork length, tyres, tilt and any attachment all change what a truck is rated to do, and the derating is not a straight line outside the conditions the plate was written for. This page handles load centre and says nothing about the rest. If there is an attachment on the carriage, the plate that applies is the one written for the truck and that attachment together — a plate for the bare truck no longer describes the machine.
Questions people ask
What is a forklift load center?
The horizontal distance from the front face of the forks to the centre of gravity of the load. The data plate rating is a weight at that distance, commonly 24 in on smaller trucks though not universally, and the pair of numbers is really a single moment. For an evenly packed load the centre sits at half the load depth.
How do I work out capacity at a different load center?
Multiply the load weight by its actual load centre to get a moment, then divide by the load centre the plate is written for. That gives the equivalent weight at plate distance. The page does this and shows both moments so you can hold them against your own plate. It does not do the comparison for you, because that belongs to the plate and a qualified person.
Why does a longer load reduce what a forklift can carry?
Because the centre of gravity moves further from the front axle and the moment grows in proportion. A 5 ft deep evenly packed load has a 30 in centre instead of the 24 in a 4 ft load has, so the same weight asks 25 percent more. Nothing was added to the load and nothing on the paperwork changed.
Is half the load depth always the load center?
Only for an evenly packed load. A motor at one end of a crate, a pallet stacked heavy at the back, an off-centre coil or a bundle overhanging the fork tips all move the real centre somewhere the outside of the load does not show. The offset field is there to make that a deliberate judgement rather than a silent assumption.
Does an attachment change the data plate?
Yes, and this page cannot know how. An attachment has weight of its own ahead of the carriage and a load centre of its own, and the plate that governs a truck with an attachment fitted is the plate written for that combination. A plate for the bare truck no longer describes the machine. The attachment fields here add its moment; they do not derate anything.
What does the steer axle number mean?
It is what is left pressing on the rear axle once the load ahead of the front axle has been subtracted from the truck weight behind it — a static moment balance on a level floor with the mast vertical and nothing moving. Tilt, braking, ramps and turning all take away from it. It shows which way the geometry is pushing. It is not a capacity and it does not set a limit.