Electrical Calculator

Calculate voltage, current, resistance, and power using Ohm's Law and Power formulas

Electrical Values
Enter any two known values to calculate the others
Calculation Results
Electrical parameters and safety analysis

Enter two electrical values to calculate the others

Common Electrical Examples
Click to load typical electrical circuit values

LED Circuit

Typical LED with current limiting resistor

Voltage: 3.3V

Current: 0.02A

Household Outlet

Standard US household appliance

Voltage: 120V

Power: 1500W

Car Battery

Automotive electrical system

Voltage: 12V

Current: 10A

USB Charger

Phone charger specifications

Voltage: 5V

Current: 2A

Motor Circuit

Small DC motor application

Voltage: 24V

Power: 250W

Electrical Formulas Reference

Ohm's Law

Voltage

V = I × R

Voltage equals current times resistance

Current

I = V ÷ R

Current equals voltage divided by resistance

Resistance

R = V ÷ I

Resistance equals voltage divided by current

Power Laws

Power (V,I)

P = V × I

Power equals voltage times current

Power (V,R)

P = V² ÷ R

Power equals voltage squared divided by resistance

Power (I,R)

P = I² × R

Power equals current squared times resistance