Ohm's Law Calculator

Calculate voltage, current, resistance, and power using Ohm's Law for electrical circuits.

Embed this tool

Select Calculation Mode

Enter Current (I) and Resistance (R)

Advertisement

Ad

Understanding Electrical Circuits

Ohm's Law is the fundamental relationship between voltage, current, and resistance in an electrical circuit. Discovered by Georg Simon Ohm in 1827, it forms the basis of all circuit analysis.

V = I × R

Where V is the voltage (electrical pressure) measured in volts, I is the current (flow of electrons) measured in amperes, and R is the resistance (opposition to flow) measured in ohms.

Electrical power (P) represents the rate at which electrical energy is transferred in a circuit. It is calculated as the product of voltage and current:

P = V × I = I² × R = V² ÷ R

Power is measured in watts (W). One watt equals one joule of energy per second. Common applications include calculating the power consumption of appliances, sizing resistors, and designing safe electrical systems.

  • Series circuits: Current is the same through all components; voltages add up.
  • Parallel circuits: Voltage is the same across all branches; currents add up.
  • Kirchhoff's Laws: Extend Ohm's Law to complex circuits with multiple loops and branches.

Always ensure your components are rated for the calculated voltage, current, and power to prevent overheating and ensure safe operation.

Frequently Asked Questions

Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them. It is expressed as V = I × R, where V is voltage, I is current, and R is resistance.

Related Tools

Unix Timestamp Converter

Convert Unix timestamps to human-readable UTC, local, and ISO 8601 dates.

Cooking Converter

Convert cooking measurements: cups, grams, tablespoons, ounces, temperatures, and more.

CM to Inches Converter

Convert centimeters to inches instantly.

Inches to CM Converter

Convert inches to centimeters and back with feet reference.