Watts to Volts Calculator

Convert watts to volts by entering power in watts and current in amps. Determine the voltage required for any electrical load. Supports DC and AC circuits with power factor.

CIRCUIT TYPE

💡 POWER (WATTS)

⚡ CURRENT (AMPS)

VOLTAGE

120 V

KILOVOLTS

0.12 kV

CIRCUIT TYPE

FORMULA

V = P / I

Watts to Volts — Reference Table

Watts	At 5A	At 10A	At 15A	At 20A
60 W	12 V	6 V	4 V	3 V
100 W	20 V	10 V	6.67 V	5 V
200 W	40 V	20 V	13.33 V	10 V
500 W	100 V	50 V	33.33 V	25 V
1,000 W	200 V	100 V	66.67 V	50 V
1,500 W	300 V	150 V	100 V	75 V
1,800 W	360 V	180 V	120 V	90 V
2,000 W	400 V	200 V	133.33 V	100 V
3,600 W	720 V	360 V	240 V	180 V
5,000 W	1,000 V	500 V	333.33 V	250 V

💡 How to Convert Watts to Volts

Converting watts to volts tells you the voltage required to deliver a certain power at a given current. This is useful for designing circuits, selecting power supplies, and troubleshooting electrical systems.

Watts to Volts Formula

DC Circuit: V = P / I
Single-Phase AC: V = P / (I × PF)
Three-Phase AC: V = P / (I × PF × √3)

Where V is voltage (volts), P is power (watts), I is current (amps), PF is power factor.

Example: Finding Voltage for a 60W Light Bulb

A 60W incandescent bulb drawing 0.5A:
V = 60W / 0.5A = 120 volts

This confirms it's designed for a standard US 120V outlet.

When You Need This Conversion

Power supply selection: Determine the output voltage needed for a specific wattage at a known current
Battery system design: Calculate whether your battery voltage is sufficient for your load
Solar panel sizing: Verify that panel voltage matches inverter requirements
Troubleshooting: Compare calculated voltage to measured voltage to identify problems

References

Principles of Electric Circuits — Thomas Floyd, 10th Edition
NFPA 70 — National Electrical Code (NEC), 2023 Edition

A 60W light bulb at 0.5 amps operates at 120 volts — the US standard. Use this calculator to verify voltage requirements for any device.