Ohm's Law Calculator
Calculate V, I, R, or P
Enter any two values to calculate the other two.
Result
| Voltage (V) | — |
|---|---|
| Current (I) | — |
| Resistance (R) | — |
| Power (P) | — |
About Ohm's Law
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. The standard formula is V = I × R.
The Formulas
Combining Ohm's Law with Joule's Law (P = V × I) gives us a complete set of formulas to calculate any variable given two others:
- Voltage (V) = I × R = P / I = √(P × R)
- Current (I) = V / R = P / V = √(P / R)
- Resistance (R) = V / I = V² / P = P / I²
- Power (P) = V × I = I² × R = V² / R