Whether the cables physically fit — conduit, boxes and the bends between them.
The calculation nobody does until the conduit is already in the wall. Fill limits exist because cables need to be pullable without damaging the insulation, and because a packed conduit cannot shed heat.
These are pure table lookups with exceptions that catch people out — the 31% two-conductor rule, pigtails counting zero in a box, grounds counting once collectively.
EMT, IMC, RMC and PVC against the real Chapter 9 areas, including the 31% case.
NEC 314.16, where what counts as a conductor is the part most calculators get wrong.
No calculator for this yet
Offsets, saddles and the shrink you have to allow for.
No calculator for this yet
The metric-world sibling of conduit fill, using BS 7671 capacity factors. Not yet built.
No calculator for this yet
1 calculator in this category. Every one is free to use on ElectroCalculators, with no account required, and every result cites the standard it came from.