You need to know the current the circuit will draw. If you are sizing a circuit for a specific appliance (like an oven or an air conditioner), check the nameplate rating. If you are sizing a circuit for multiple points (like a lighting circuit or general-purpose outlet circuit), you must calculate the demand according to .
I_z = I_table × C_t × C_g × C_i × C_c × C_d cable size calculator australia
In Australia, we refer to cable size in square millimetres (), which refers to the cross-sectional area of the copper. However, some overseas calculators or hardware store labels might use the diameter (mm). You need to know the current the circuit will draw
| Cross-section (mm²) | Typical applications (copper, 230V) | |---------------------|---------------------------------------| | 1.0 | Lighting circuits (≤10A) | | 1.5 | Lighting, small fans (≤15A) | | 2.5 | Power outlets (≤20A), general GPOs | | 4.0 | Fixed appliances (≤25A), ovens, AC units | | 6.0 | 32A cooktops, instantaneous HWS | | 10 | 40–50A sub-mains | | 16 | 63A sub-mains or EV chargers | | 25–35 | 80–100A main switchboards | | 50+ | Large mains, industrial supplies | I_z = I_table × C_t × C_g ×