How to convert electrical voltage in volts (V) to electric current in amps (A).
You can calculate amps from volts and watts or ohms, but you can't convert volts to amps since volt and amp units represent different quantities.
Volts to amps calculation with watts
The current I in amps (A) is equal to the power P in watts (W) , divided by the voltage V in volts (V):
I(A) = P(W) / V(V)
So
amp = watt / volt
or
A = W / V
Example
What is the current flow of an electrical circuit that has power consumption of 45 watts and voltage supply of 15 volts?
I = 45W / 15V = 3A
Volts to amps calculation with ohms
The current I in amps (A) is equal to the voltage V in volts (V) divided by the resistance R in ohms (Ω):
I(A) = V(V) /
R(Ω)
So
amp = volt / ohm
or
A = V / Ω
Example
What is the current flow of an electrical circuit that has voltage supply of 30 volts and resistance of 10Ω?
According to ohm's law the current I is equal to 30 volts divided by 10 ohms:
I = 30V / 10Ω = 3A