Ohm's Law Calculator
Calculate voltage, current, resistance using V = IR
How to Use
- Select what you want to calculate (voltage, current, or resistance)
- Enter the two known values in the input fields
- Choose the appropriate units for each value
- Click calculate to get the third value and power
- View the results in multiple units for convenience
- Copy the results to your clipboard for later use
About This Tool
Our free Ohm's Law calculator uses the fundamental electrical formula V = IR (voltage equals current times resistance) to solve circuit problems. Whether you need to calculate voltage, current, or resistance, this calculator handles it all. It also calculates power (P = VI) automatically, giving you a complete picture of your circuit. Perfect for students, electricians, engineers, and hobbyists working with electronics. The calculator supports multiple units including volts, millivolts, kilovots; amperes, milliamperes, kiloamperes; and ohms, kilohms, megohms. All calculations happen instantly in your browser with complete privacy.
Frequently Asked Questions
What is Ohm's Law?
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points, expressed as V = IR, where V is voltage, I is current, and R is resistance.
What units does this calculator support?
Our Ohm's Law calculator supports volts, millivolts, and kilovolts for voltage; amperes, milliamperes, and kiloamperes for current; and ohms, kilohms, and megohms for resistance.
Can I calculate power as well?
Yes, the calculator automatically calculates power (P = VI) along with voltage, current, and resistance. Power is measured in watts.
What are the practical applications of Ohm's Law?
Ohm's Law is used extensively in electronics for circuit design, troubleshooting, and analysis. It helps calculate component values, determine current flow, and ensure safe operating conditions.
