Ohm's Law Calculator
Ohm's law and power calculator: enter any two of voltage, current, resistance and power to get the others.
How to use the Ohm's Law Calculator
- Fill in what you know of: Voltage V, Current I, Resistance R, Power P — leave the unknown empty.
- The results (Voltage, Current, Resistance, Power) are calculated instantly as you type.
- Use “Copy link” to share the calculation with the same input values.
Formula
- V = I·R
- P = V·I = I²R = V²/R
About this tool
Leave the unknown fields empty. Exactly two known values are needed.