Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law. Fill any 2 fields to find the other 2.
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Quickly calculate voltage, current, resistance, and power using Ohm's Law. Simply enter any two values and the tool instantly computes all four electrical quantities, perfect for circuit design, troubleshooting, and electrical learning.
How it works
- 1Enter any two electrical values from voltage, current, resistance, or power
- 2The calculator instantly computes the remaining two values using Ohm's Law
- 3View the formulas used to show the mathematical relationships
- 4Use results for your circuit design or troubleshooting needs
Who uses this tool
- ✓Electronics hobbyists designing and testing circuits
- ✓Students learning electrical theory and Ohm's Law fundamentals
- ✓Electricians troubleshooting power issues in installations
- ✓Engineers verifying component specifications and power ratings
- ✓DIY makers calculating resistor values for LED and component projects
Frequently Asked Questions
What is Ohm's Law?
Ohm's Law states that V = I × R — Voltage equals Current multiplied by Resistance. It's fundamental to all electrical circuit analysis.
How do I use the calculator?
Enter any two known values (V, I, R, or P) and the calculator will solve for the other two automatically.
What is Power in this context?
Electrical power P = V × I (watts). It represents the rate of energy consumption or generation in a circuit.
What units should I use?
Use Volts (V), Amperes (A), Ohms (Ω), and Watts (W). The calculator works with any consistent set of SI units.