Electrical Calculator — Ohm's Law
Calculate Voltage (V), Current (I), Resistance (R), and Power (P) using Ohm's Law. Enter any two known values to instantly find the remaining two.
Ohm's Law Calculator
Enter any 2 known values — the other 2 will be calculated using V = IR and P = VI.
Results
Enter 2 values and click Calculate
Ohm's Law Formulas
Ohm's Law describes the relationship between voltage, current, and resistance in an electrical circuit. Combined with the power formula, any two of the four quantities determine the other two.
Core Formulas:
- V = I × R — Voltage equals Current times Resistance
- I = V / R — Current equals Voltage divided by Resistance
- R = V / I — Resistance equals Voltage divided by Current
- P = V × I — Power equals Voltage times Current
- P = I² × R — Power from Current and Resistance
- P = V² / R — Power from Voltage and Resistance
Units:
- Voltage (V): Volts (V)
- Current (I): Amperes (A)
- Resistance (R): Ohms (Ω)
- Power (P): Watts (W)