Watts to Volts Calculator

Enter your Power and Current values, choose your Current Type (AC or DC), and adjust the Power Factor or System Impedance if needed — the Watts to Volts Calculator works out your Voltage along with the exact formula used and your Power in Watts.

W
A

Only required for AC circuits (0.1 to 1.0)

Ω

Used when calculating with impedance

Results

Voltage

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Formula Used

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Power in Watts

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Results Table

Frequently Asked Questions

What is the formula to convert watts to volts?

For DC circuits: V = P / I (voltage equals power divided by current). For AC single-phase: V = P / (PF × I) where PF is power factor. For AC three-phase: V = P / (√3 × PF × I).

What is a watt?

A watt (W) is the unit of power in the International System of Units. It measures the rate of energy transfer and is equivalent to one joule per second. In electrical terms, one watt equals one volt times one ampere.

What is a volt?

A volt (V) is the unit of electrical potential difference or voltage. It represents the potential difference that drives one ampere of current through a resistance of one ohm, consuming one watt of power.

Do I need to know the power factor for DC calculations?

No, power factor is only required for AC circuits. DC circuits use the simple formula V = P / I. Power factor accounts for the phase difference between voltage and current in AC systems.

What is system impedance and when do I use it?

System impedance (measured in ohms) is the total opposition to current flow in a circuit. Use impedance when you know the power and impedance but not the current, using the formula V = √(P × Z).

Can I convert milliwatts to volts?

Yes, the calculator supports milliwatts (mW), watts (W), and kilowatts (kW). Simply select the appropriate power unit and the calculation will be adjusted automatically.

What's the difference between single-phase and three-phase AC calculations?

Single-phase AC uses V = P / (PF × I), while three-phase AC uses V = P / (√3 × PF × I). Three-phase systems include the factor √3 (approximately 1.732) because power is distributed across three phases.

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