- Enter Two Values — Any two of Voltage (V), Current (A), Resistance (Ω), or Power (W).
- Calculate — The other two values are computed instantly.
- View Formulas — See which formulas were used.
Ohm's Law Calculator — Electrical Engineering Tool
The Ohm's Law Calculator lets you enter any two of four electrical values — Voltage (V), Current (I), Resistance (R), and Power (P) — to instantly calculate the other two. It's an essential tool for electronics engineers, students, and hobbyists.
Ohm's Law Explained
Ohm's Law is the fundamental relationship in electrical circuits: V = I × R. Georg Simon Ohm discovered that the current through a conductor is directly proportional to the voltage across it and inversely proportional to its resistance.
The Four 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
Extended Power Formulas
- P = I² × R — Power from Current and Resistance
- P = V² / R — Power from Voltage and Resistance
- V = √(P × R) — Voltage from Power and Resistance
- I = √(P / R) — Current from Power and Resistance
Features
- Any Two → Other Two — 6 input combinations supported.
- Formula Display — Shows which formulas were used.
- Visual Highlighting — Calculated values are highlighted.
- Copy Results — One-click clipboard copy.
Privacy
All calculations run in your browser. No data is transmitted.