Ohm's Law Calculator
Calculate voltage, current, resistance, and power with ease. Perfect for electronics engineers, students, and hobbyists.
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Understanding Ohm's Law
Ohm's Law is one of the most fundamental principles in electrical engineering, discovered by German physicist Georg Ohm in 1827. It describes the relationship between voltage, current, and resistance in an electrical circuit.
The Water Analogy
Think of electricity like water flowing through a pipe:
- Voltage (V) is like water pressure pushing the water through
- Current (I) is like the flow rate of water
- Resistance (R) is like the pipe's width - narrower pipes resist flow more
The Magic Triangle
The Ohm's Law triangle is a helpful memory tool. Cover the value you want to calculate:
- • V (Voltage) = I × R
- • I (Current) = V ÷ R
- • R (Resistance) = V ÷ I
Power in Electrical Circuits
Power (P) is the rate at which electrical energy is transferred. It can be calculated using several formulas:
- P = V × I
- P = I² × R
- P = V² ÷ R
Real-World Example:
A 60W light bulb connected to 120V:
- • Power (P) = 60 watts
- • Voltage (V) = 120 volts
- • Current (I) = P÷V = 60W÷120V = 0.5A
- • Resistance (R) = V÷I = 120V÷0.5A = 240Ω
Common Applications
Electronics Design
Calculating proper resistor values for LEDs and other components
Power Supply
Determining current requirements for circuits and devices
Troubleshooting
Identifying issues in circuits by measuring voltage drops