For specifiers
How many ceiling mounting points does a light fixture need
The number follows not from weight or diameter, but from how the suspension is built.
If the fitting is a single body, a housing with one canopy, the whole mass arrives at a single node, and the number of points is set by that fitting's own manufacturer. If it is a composition of elements on cables, it needs as many points as there are elements, because each element hangs on its own line and meets the ceiling at its own point.
One qualification, and it points upwards: a heavy element may hang on several lines rather than one — how many is decided at the factory for the specific piece. So for light elements, which are the vast majority, the equality is exact; for heavy ones the number of elements is a lower bound — as many points or more, but never fewer.
That is the answer usually replaced by “refer to the manufacturer specification”, a document almost nobody publishes. The number follows not from weight or diameter but from how the suspension is built.
Why a composition is different
In a single-body fixture the whole mass reaches one node, and the only question is whether that node holds. In a composition the mass is spread out: a hundred elements mean a hundred lines and a hundred separate nodes. The share of the mass reaching each point is smaller than for a single fitting of the same weight, but there are many points, so the setting out has to be known at design stage rather than worked out on site.
Exceptions
SKUs where one element does not mean one point. For most SKUs the count matches one to one; where an element is suspended on more than one line, there are more points than elements.
Threaded columns
The elements are threaded onto one line: the whole column arrives at a single point on the plan, however many pieces of glass it holds.
Frame
The elements hang on a frame, and the ceiling is drilled for the frame itself — it sets the points, not the element count.
On a rod
The discs are carried by a curved rod, and the composition itself hangs on several cables and several wires. The number of cables follows the size of the composition; the number of wires follows the size and the count of lit discs. There are fewer points than elements here, but there are points.
How to get the number for your own ceiling
The configurator assembles the composition to the dimensions you give and returns:
Values are calculated by the configurator engine from the actual composition layout. Verification of the slab's load-bearing capacity and selection of fixings is the specifier's responsibility.