Motor current power calculation

Motor current calculation formula:

Single-phase motor current calculation formula

I = P / (U*cosfi)
For example: single-phase voltage U=0.22KV, cosfi=0.8 then I=P/(0.22*0.8)=5.68P

Three-phase motor current calculation formula

I = P / (1.732*U*cosfi)
For example: three-phase voltage U=0.38KV, cosfi=0.8 then I=P/(1.732*0.38*0.8)=1.9P
According to experience 220V: KW/6A, 380V: KW/2A, 660V: KW/1.2 A, 3000V: 4KW/1A

Motor power calculation formula: (common three-phase motor power calculation)

Among them, P1(W) is the three-phase motor power, U(V) is the line voltage, I(A) is the line current, and the cosφ power factor is often taken as 0.8

△ delta connection method, the calculation formula is: P2 = 3*P1
which is three times the power of the three-phase power Y connection method.

Calculate motor current


Efficiency value (%)

P.F (%)


Since the supply voltage cannot be maintained at 380V or 220V at all times,
The current also changes with voltage

Calculate motor power


Efficiency value (%)

P.F (%)


Calculate kVA (for 3-phase motors)



P.F (%)

This calculator can perform online calculation functions such as motor current and motor power.