Ohm's Law states that Voltage (V) = Current (I) × Resistance (R). It describes the relationship between voltage, current, and resistance in a circuit.

How do I calculate amps from volts and ohms?

I = V / R. Divide voltage by resistance to get current. For example, 120V across 8 ohms = 15 amps.

How do I calculate watts using Ohm's Law?

Power (watts) = Voltage × Current (P = VI). You can also use P = I²R or P = V²/R when you only know two values.

What is the Ohm's Law wheel?

The Ohm's Law wheel (or power wheel) shows all 12 formulas relating V, I, R, and P, making it easy to find any value from any two known quantities.

Does Ohm's Law work for AC circuits?

Ohm's Law applies to DC circuits directly. For AC circuits, impedance (Z) replaces resistance, and phase angles must be considered for reactive components.

Ohm's Law Calculator — Solve V, I, R & Watts

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Quick Answer

Ohm's Law states that Voltage (V) equals Current (I) times Resistance (R) — enter any two values and the third is calculated automatically. This tool also shows Power (P = V × I) in watts and kilowatts.

Use the Ohms Law Calculator below to get instant results.

Ohm's Law Calculator

Fill in any two fields to calculate the third. Also shows power (watts). V = IR, I = V/R, R = V/I, P = VI.

Voltage — V (volts): Current — I (amps): Resistance — R (ohms Ω):

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Cite This Tool

Ohms Law Calculator. (2026). Electrical Calculators Online. Retrieved from https://electricalcalcpro.com/ohms-law-calculator/

Ohm's Law Calculator

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