Ohm's Law Calculator
Enter voltage and resistance to calculate current and power using Ohm’s Law.
Ohm's Law Calculator
Calculate current and power from voltage and resistance using Ohm's Law.
This is a mathematical calculation based on ideal Ohm’s Law behavior and does not account for real-world factors like temperature-dependent resistance.
Ohm's Law describes the relationship between voltage, current and resistance in an electrical circuit: voltage equals current times resistance. This calculator takes voltage and resistance and calculates the resulting current, along with power using the related formula P = V²/R.
Example
- With the default values shown above, this calculator returns: Current ≈ 3.000; Power ≈ 36.000.
Frequently Asked Questions
What is Ohm’s Law?
Ohm's Law states that voltage (V) equals current (I) times resistance (R), usually written as V = IR — rearranging it gives current as voltage divided by resistance.
How is power calculated here?
Power equals voltage squared divided by resistance (P = V²/R), a form of the power formula P = VI derived by substituting Ohm’s Law.