Ohm’s Law Current Calculator
I = V ÷ R • Power and conductance from voltage and resistance
Voltage may be positive or negative.
Resistance must be greater than 0.
Quick summary
Enter voltage and resistance, then click Calculate.
Results
Current
— A
Power
— W
Conductance
— S
Results are calculated from volts and ohms in SI units.
Use this Ohm’s Law Current Calculator to calculate electric current from voltage and resistance. It also shows electrical power and conductance.
Calculation Method
Current = Voltage ÷ Resistance
I = V ÷ R
Related calculations:
Power = V × I
Conductance = 1 ÷ R
Example
For a 12 V supply and 6 Ω resistance:
I = 12 ÷ 6 = 2 A
Power = 12 × 2 = 24 W
Important Note
Ohm’s law applies to components or circuit conditions with an approximately Ohmic relationship. LEDs, diodes, transistors, AC impedance, temperature effects, and other real-world factors may require additional analysis.
The calculated current does not confirm that a circuit, wire, resistor, power supply, or electrical installation is safe.