Note · 21 August 2026
Same rating, different machine
Three loaders, one capacity figure, three different derivations.
Three machines advertised at the same operating capacity, a wheeled skid steer, a compact track loader and an articulated wheel loader, are not equivalent, because the number was arrived at three different ways. The skid steer’s figure is half its measured tipping load under SAE J818. The track loader’s is conventionally 35 per cent of its tipping load, so an equal rating implies a substantially higher one.
The wheel loader may be described by static tipping load at full articulation, which is not a rated capacity at all but the tipping point itself. Every figure is correct and published in good faith; only the comparison between them is wrong.
Put three machines side by side, each advertised at the same operating capacity. A wheeled skid-steer loader, a compact track loader, and an articulated compact wheel loader. The number on all three specification sheets is identical.
The machines are not equivalent, and the reason is that the number was arrived at three different ways.
Three methods behind one number
The wheeled skid steer's figure is rated operating capacity under SAE J818: the machine is loaded until its rear wheels lift, that is the tipping load, and the rating is half of it. The track loader's figure is rated operating capacity too, but tracked machines are conventionally rated at 35 per cent of tipping load rather than 50, because tipping behaviour on tracks gives less warning. The wheel loader may be described by static tipping load at full articulation: a different measurement again, taken with the machine bent rather than straight, because that is when an articulated machine is least stable.
So the same printed number describes a machine that will lift twice that in a test, a machine that will lift nearly three times it, and a machine whose figure is not a rated capacity at all but the point of tipping itself. A buyer comparing the three on the headline is comparing three different quantities.
| Machine | What the headline figure is | Implied tipping load |
|---|---|---|
| Wheeled skid steer | Rated operating capacity: 50% of measured tipping load, per SAE J818 | Twice the quoted figure |
| Compact track loader | Rated operating capacity: conventionally 35% of measured tipping load | Nearly three times the quoted figure |
| Compact wheel loader | Often static tipping load at full articulation: the tipping point itself | The quoted figure is the tipping load |
This is not deception, and that is the interesting part
Every one of those figures is correct, published in good faith, and derived by an established method. Nobody is hiding anything. The confusion arises entirely because three legitimate conventions, developed for three machine types by different standards processes at different times, produce a number that looks like the same kind of thing.
This is what a rating standard does and does not promise. It promises that two machines of the same type, rated by the same method, are comparable, which provides a defined basis for comparison between the two machines. It promises nothing at all about comparability across types, and it was never intended to.
What to compare instead
Where machines of different types are being considered for the same specified task for the same job, the comparison supported by the recorded measurements is the underlying measurement rather than the derived rating. Tipping load is published or derivable for all three, and it is the same physical quantity in every case.
Even then, the comparison is incomplete without the conditions each was measured under: the attachment fitted, and for the articulated machine, whether it was straight or bent. A tipping load measured with a bucket does not describe the machine carrying pallet forks, and the Pallet forks: load centre effect is large.
The broader lesson generalises past loaders. Any time a specification looks directly comparable between two different kinds of machine, the first question is whether the two figures were produced by the same procedure. On this equipment the answer is often no, and the difference is rarely in the direction you would guess.
Straight answers
Same rating, different machine: Questions and answers
Can I compare rated operating capacity between a skid steer and a track loader?
Not directly, and the error runs in a consistent direction. A wheeled skid steer is rated at half its measured tipping load under SAE J818; a tracked machine is conventionally rated at 35 per cent of its tipping load, because tipping on tracks gives less warning. Two machines quoting the same rating therefore do not have the same tipping load.
The tracked one is substantially higher, so the naive comparison understates it.
Is a manufacturer being deceptive by quoting these figures?
No, and that is what makes the problem interesting. Each figure is correct, published in good faith, and derived by an established method. The confusion comes from three legitimate conventions, developed for three machine types by different standards processes at different times, producing numbers that look like the same kind of thing.
Nobody has to be acting badly for the comparison to mislead.
What should I compare across different loader types?
The underlying measurement rather than the derived rating. Tipping load is the same physical quantity for all three types and it is published or derivable in each case. Even then, note the conditions: which attachment was fitted, and for an articulated machine whether it was measured straight or fully bent.
A tipping load measured with a bucket does not describe the same machine carrying pallet forks.
Does this problem occur outside loader ratings?
Frequently. Any time a specification appears directly comparable between two different kinds of machine, the first question worth asking is whether the two figures were produced by the same procedure. On this equipment the answer is often no, horsepower measured at three points in a driveline is another example, and the difference is rarely in the direction intuition suggests.
Why is a wheeled skid steer rated at 50% of tipping load while a tracked one is rated at 35%?
Because tipping behaviour differs by undercarriage: a wheeled machine gives more warning as it approaches its tipping point, while a tracked machine's tipping onset is more abrupt, so the industry convention builds in a larger safety margin (a lower percentage of the actual tipping load) for tracked machines specifically because of that reduced warning.
Is there a way to independently verify a manufacturer's published tipping load figure?
Not practically for an individual buyer: tipping load is measured under controlled test conditions specified by the relevant standard (SAE J818 for skid steers, ISO 14397-1 for loaders and backhoe loaders), and reproducing that test is not something an owner can do; the reasonable check is confirming which standard and method a manufacturer states it used, not re-measuring the figure yourself.
Does attachment weight get factored into the published rated operating capacity?
Generally not into the base published rating itself, which describes the bare machine's capacity: a heavier attachment reduces what the machine can then carry as payload within that rating, the same relationship covered on the lift-capacity page, so the attachment's own weight has to be subtracted from the rated figure to find the actual usable payload.
Why does this note say the difference "is rarely in the direction you would guess"?
Because the intuitive assumption is that a more conservative-looking percentage (35% for tracked machines) implies a smaller or weaker machine, when the opposite is often true: the lower percentage exists precisely because the tracked machine's actual tipping load, and often its real capability, is higher, not lower, than a same-numbered wheeled machine's.
Who decides which percentage of tipping load a manufacturer uses to rate a machine?
The relevant engineering standards body, SAE International for skid-steer loaders under J818, ISO for loaders and backhoe loaders under ISO 14397-1, publishes the method, and manufacturers apply it to their own tested tipping load; the percentage itself (50% wheeled, conventionally 35% tracked) is an industry convention within that framework rather than a figure each manufacturer sets independently.
Does this same three-methods problem apply when comparing an excavator's lift capacity to a loader's?
Yes, in spirit: an excavator's capacity is charted rather than given as a single rated figure precisely because it varies continuously with reach and rotation, so comparing an excavator's chart value at one position to a loader's single rated figure is exactly the kind of cross-type comparison this note warns is rarely apples-to-apples.
Is there a universal capacity rating method being developed to replace these three different conventions?
This note is not aware of an imminent unification, and given that each convention was developed for different machine geometries and support layouts and stability behaviors (wheeled versus tracked versus articulated), a single universal method would need to account for those real physical differences rather than simply picking one existing convention for all three.
Does this note's lesson apply to comparing two machines within the same category, like two wheeled skid steers?
Less so: two wheeled skid steers both rated under SAE J818 at 50% of tipping load can be compared on that stated rating, since they share the same measurement convention; the caution in this note is specifically about comparing ACROSS machine types (wheeled versus tracked versus articulated), not within one.