Enter any two known values — leave the unknowns blank. All four quantities will be calculated.
| Find | Known | Formula |
|---|---|---|
| Voltage (V) | I, R | V = I × R |
| Voltage (V) | P, I | V = P / I |
| Voltage (V) | P, R | V = √(P × R) |
| Current (I) | V, R | I = V / R |
| Current (I) | P, V | I = P / V |
| Current (I) | P, R | I = √(P / R) |
| Resistance (R) | V, I | R = V / I |
| Resistance (R) | V, P | R = V² / P |
| Resistance (R) | P, I | R = P / I² |
| Power (P) | V, I | P = V × I |
| Power (P) | I, R | P = I² × R |
| Power (P) | V, R | P = V² / R |