Multiple load calculator

Connected load is simply quantity × rated watts for every device, added up. It is the figure the distribution utility uses on your connection application, and it is always higher than what you actually draw, because you never switch everything on at once.

Maximum demand applies a diversity factor to the connected load. A typical residential flat runs at 55–70% diversity, a shop at 70–85%, and a small workshop with motors at 80–90%. Utilities in Bangladesh bill demand charges to MT and HT consumers on this diversified demand, not the connected total.

Line current uses I = P ÷ (V × pf) for single phase and I = P ÷ (√3 × V × pf) for three phase. Inductive loads such as motors, compressors and older fans push the power factor down toward 0.75–0.85, which raises current for the same kilowatts — that is why the calculator lets you set it.

Breaker size is the next standard MCB rating above 125% of the calculated current, following the usual continuous-load allowance. Treat it as a sanity check, not a design document: final selection must account for cable size, ambient temperature, fault level and the actual layout of your distribution board.

Monthly units multiply average draw (rated watts × duty factor) by hours per day and days per month. Duty factor matters enormously for anything with a compressor: a fridge is plugged in 24 hours but its compressor runs roughly a third of the time, and an inverter AC settles at 40–60% of rated power once the room is cool.