Electrical Calculator
Solve Ohm's Law for voltage, current, resistance, and power. Enter any two values to calculate the rest.
= 12.00 V
= 2.000 A
= 6.000 Ω
= 24.00 W
Ohm's Law Reference
What Is the Electrical Calculator?
The Electrical Calculator solves Ohm's Law equations for voltage (V), current (I), resistance (R), and power (P). Enter any two known values and the calculator instantly derives the other two using the fundamental relationships: V = I × R and P = V × I.
How to Use
- Enter any two of the four values: Voltage (V), Current (I), Resistance (R), or Power (P)
- The remaining two values are calculated automatically
- Clear a field to change which values are known
- Results are shown with appropriate SI prefixes (k, M, m, µ)
Ohm's Law Formulas
- V = I × R
- I = V / R
- R = V / I
- P = V × I = I² × R = V² / R
FAQ
What units does this use?
Volts (V), Amperes (A), Ohms (Ω), and Watts (W). Results are displayed with SI prefixes: k (×1000), M (×1,000,000), m (×0.001), µ (×0.000001).
Does this work for AC circuits?
These formulas apply to DC circuits and resistive AC loads. For reactive AC circuits (with capacitors or inductors), impedance (Z) replaces resistance and power factor must be considered.
Why do I need to enter exactly two values?
Ohm's Law has four variables and two independent equations, so two known values are needed to uniquely determine the other two.