Ohm's Law Calculator

Calculate voltage, current, resistance, and power using Ohm's law.

Voltage (V)

Current (A)

Results

Resistance (Ω)6

Power (W)24

Energy in 1 hour (Wh)24

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What is Ohm's Law?

Ohm's Law states that voltage equals current times resistance (V = IR). It's the most fundamental law in electrical engineering and electronics.

Combined with the power formula (P = VI), these four quantities — voltage, current, resistance, and power — form the Ohm's Law wheel used by every electrician and engineer.

Formula

V = I × R (Voltage = Current × Resistance) I = V / R (Current = Voltage / Resistance) R = V / I (Resistance = Voltage / Current) P = V × I (Power = Voltage × Current) P = I² × R P = V² / R

How to use this Ohm's Law Calculator?

1. Enter voltage and current. 2. See calculated resistance and power. 3. Use these for circuit design and troubleshooting.

Frequently asked questions

What is 1 Ohm?

1 Ohm is the resistance that allows 1 Ampere of current to flow when 1 Volt is applied across it.

What is the difference between AC and DC?

DC (Direct Current) flows in one direction (batteries). AC (Alternating Current) reverses direction periodically (wall outlets, 50 Hz in India). Ohm's Law applies to both.

How much current is dangerous?

Current above 10 mA (0.01 A) across the heart can be fatal. This is why electrical safety is critical — 230V AC at even small currents can be deadly.

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