Three different heights with the same name
Where the work is, where the platform floor has to be, and what the machine is called are three numbers and they are all different. Work the defaults through. The work is 38 feet up. You reach about 5 feet above the platform floor to do it, so the floor has to be at 33 feet — that is the platform height a chart states. Charts also publish a working height that adds a fixed allowance, six feet in this example, so the same machine is advertised at 39 feet.
Which means a job at 38 feet needs a machine described as a 39, and a machine described as a 40 puts the floor at 34. Hire desks quote the advertised number, charts use the platform number, and the job cares about neither. The allowance is a convention and it is not identical everywhere, which is why this page asks you to enter it off the chart in front of you rather than assuming a figure.
Outreach is measured from somewhere you cannot see
The horizontal figure on a reach chart is almost always measured from the centre of rotation — the middle of the turret — and not from the front bumper. So the stand-off you measure on the ground is not the outreach the chart is talking about. Fourteen feet of stand-off with the centre of rotation four feet inside the machine edge is eighteen feet of chart outreach, and if you size off the fourteen you will be short by the width of half a machine.
Outreach also shrinks as the boom rises. A chart is an envelope, not a pair of maximums, and the maximum height and the maximum reach are never available at the same time. Taking the two headline numbers off a specification sheet and assuming you get both is the single most common way a machine turns up and cannot do the job.
The take-off nobody does until the truck arrives
Width against the tightest opening, length against the trailer deck, and tail swing against whatever is behind the machine when the turret turns. The default numbers here give a 5.8 foot machine through a 6 foot gate, which is 2.4 inches of total clearance — 1.2 inches a side if it is dead centre and the posts are plumb, which they are not.
Tail swing is the one that gets forgotten because it is behind the operator and it only exists when the machine is working. Three and a half feet of tail sweeps a seven foot circle, and what sits in that circle is usually somebody parked car or a section of wall that was never in the plan.
Why there is no verdict on this page
Because a reach chart point is not a number, it is a number plus its conditions: one machine, one configuration, a stated platform load, level ground, a specified axle or outrigger arrangement. Change any of those and you are on a different part of the chart or off it. A page that compared your work point to a chart figure and said yes would be encouraging exactly the reading that charts are drawn to prevent, and it would be doing it without knowing the ground, the load in the basket, or what else is in the airspace.
So the chart figures you enter are restated and nothing else is done with them. The genuinely useful output is the conversion — turning where the work is into the units a chart uses, before the machine is ordered rather than after it is on site.
Related arithmetic that also stops short of a verdict: the outrigger pad calculator for the ground, and the truss point load calculator for the overhead version of the same problem.
Questions people ask
What is the difference between platform height and working height?
Platform height is the height of the platform floor and it is what reach charts use. Working height is platform height plus a fixed allowance meant to represent a person standing on it, and it is what the machine is advertised as. The allowance is a convention rather than a measurement, so take it off the chart you are using; six feet is a figure often seen but it is not universal.
Why does my lift not reach as far out as the spec sheet says?
Because maximum height and maximum horizontal outreach are different points on the same envelope and you cannot have both at once. Outreach falls away as the boom goes up. The number to take off the chart is the outreach at the height you actually intend to work at, and on many machines that is a good deal less than the headline figure.
Where is horizontal outreach measured from?
Normally from the centre of rotation, which sits inside the machine rather than at its edge. If you measure a stand-off on the ground you have to add the distance from the machine edge back to the turret centre before comparing it to a chart. Missing that step under-states the reach required by roughly half a machine.
Can this calculator tell me which lift to hire?
No. It converts the work point into platform height and outreach so you can read a chart properly, and it restates whatever chart figures you enter without comparing them to anything. Whether a machine covers a work point depends on the configuration, the platform load, the ground and the chart for that exact model, and it is a question for the supplier and for an operator trained on the machine.
What is tail swing and why does it matter for setup?
It is how far the counterweight sweeps out behind the centre of rotation when the turret turns. A machine with three and a half feet of tail needs a seven foot circle clear behind it, and that clearance only becomes necessary once work starts — which is why a machine that parked fine can still strike a wall, a vehicle or a person the first time the boom is slewed.