Ohm's Law Calculator

Calculate voltage, current, resistance, and power using Ohm's Law. Essential tool for electronics and electrical engineering.

Ohm's Triangle

VIR×

V = I × R

I = V / R

R = V / I

calculators.ohmsLaw.calculated.resistance

6.00 Ω

Voltage (V)

12.00 V

Current (A)

2.0000 A

Resistance (Ω)

6.00 Ω

Power (W)

24.00 W

P = V × I or P = I² × R or P = V² / R

P = V × I

12.00 × 2.0000 = 24.00 W

P = V² / R

144.00 / 6.00 = 24.00 W

P = I² × R

4.000000 × 6.00 = 24.00 W

milliamps

2000.00 mA

Common Values

USB Power (5V)5V / 0.5-3A
Car Battery12V
US Household (120V)120V / 15-20A
EU Household (230V)230V / 13-16A

What is Ohm's Law?

Ohm's Law describes the relationship between voltage, current, and resistance in an electrical circuit. It states that current is directly proportional to voltage and inversely proportional to resistance.

Ohm's Law Formula

V = I × R (Voltage = Current × Resistance). This fundamental equation relates the three key electrical quantities.

Practical Applications

Ohm's Law is used in circuit design, calculating component values, determining power requirements, and troubleshooting electrical systems.