# Watts to Volts Conversion Calculator

Convert watts to volts by entering the wattage and current in amps or the circuit resistance below.

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## How to Convert Watts to Volts

Watts can be converted to volts using current and the Watt’s Law power formula, which states that current is equal to power divided by voltage. We can change this formula around by multiplying both sides by the voltage and restating it as the voltage is equal to the power divided by the current.

### Watts to Volts Formula

Thus, the following formula to convert wattage to voltage is derived:

V_{(V)} = P_{(W)} / I_{(A)}

The voltage *V* in volts is equal to the power *P* in watts divided by the current *I* in amps. We can use this formula to solve for voltage by dividing the wattage by the amperage.^{[1]}

**For example,** let’s convert 20 watts to volts using a DC circuit with 4 amps of current.

Voltage_{(V)} = 20 W ÷ 4 A

Voltage_{(V)} = 5 volts

## Conversion For AC Circuits

Converting real wattage to RMS voltage on an AC circuit is pretty similar to a DC circuit, with a slight change to account for the power factor of an AC circuit.

V_{(V)} = P_{(W)} / I_{(A)} × PF

For an AC circuit, the voltage *V* in volts is equal to the real power *P* in watts divided by the product of the current *I* in amps and the power factor.

**For example,** let’s convert 1,300 watts to voltage for an AC electrical circuit with 12 amps of current and a power factor of 0.9.

V_{(V)} = 1,300 W ÷ (12 A × 0.9)

V_{(V)} = 120.4 volts

In this example, 1,300 watts is equal to 120.4 volts at 12 amps.

## Convert Watts to Volts using Resistance

You can also convert watts to volts if the resistance of the circuit is known. Voltage is equal to the square root of the wattage times the resistance in ohms.

V_{(V)} = √(P_{(W)} × R_{(Ω)})

So, the voltage *V* in volts is equal to the square root of the power *P* in watts times the resistance *R* in ohms.^{[2]}

**For example,** let’s convert 40 watts to volts for a DC circuit with 10 ohms of resistance.

V_{(V)} = √(40 W × 10 Ω)

V_{(V)} = √400

V_{(V)} = 20 volts

## Watts to Volts Conversion Chart

Power | Voltage | Current |
---|---|---|

5 watts | 5 volts | 1 amp |

5 watts | 2.5 volts | 2 amps |

5 watts | 1.667 volts | 3 amps |

5 watts | 1.25 volts | 4 amps |

10 watts | 10 volts | 1 amp |

10 watts | 5 volts | 2 amps |

10 watts | 3.333 volts | 3 amps |

10 watts | 2.5 volts | 4 amps |

15 watts | 15 volts | 1 amp |

15 watts | 7.5 volts | 2 amps |

15 watts | 5 volts | 3 amps |

15 watts | 3.75 volts | 4 amps |

20 watts | 20 volts | 1 amp |

20 watts | 10 volts | 2 amps |

20 watts | 6.667 volts | 3 amps |

20 watts | 5 volts | 4 amps |

25 watts | 25 volts | 1 amp |

25 watts | 12.5 volts | 2 amps |

25 watts | 8.333 volts | 3 amps |

25 watts | 6.25 volts | 4 amps |

30 watts | 30 volts | 1 amp |

30 watts | 15 volts | 2 amps |

30 watts | 10 volts | 3 amps |

30 watts | 7.5 volts | 4 amps |

35 watts | 35 volts | 1 amp |

35 watts | 17.5 volts | 2 amps |

35 watts | 11.667 volts | 3 amps |

35 watts | 8.75 volts | 4 amps |

40 watts | 40 volts | 1 amp |

40 watts | 20 volts | 2 amps |

40 watts | 13.333 volts | 3 amps |

40 watts | 10 volts | 4 amps |

45 watts | 45 volts | 1 amp |

45 watts | 22.5 volts | 2 amps |

45 watts | 15 volts | 3 amps |

45 watts | 11.25 volts | 4 amps |

50 watts | 50 volts | 1 amp |

50 watts | 25 volts | 2 amps |

50 watts | 16.667 volts | 3 amps |

50 watts | 12.5 volts | 4 amps |

55 watts | 55 volts | 1 amp |

55 watts | 27.5 volts | 2 amps |

55 watts | 18.333 volts | 3 amps |

55 watts | 13.75 volts | 4 amps |

60 watts | 60 volts | 1 amp |

60 watts | 30 volts | 2 amps |

60 watts | 20 volts | 3 amps |

60 watts | 15 volts | 4 amps |

65 watts | 65 volts | 1 amp |

65 watts | 32.5 volts | 2 amps |

65 watts | 21.667 volts | 3 amps |

65 watts | 16.25 volts | 4 amps |

70 watts | 70 volts | 1 amp |

70 watts | 35 volts | 2 amps |

70 watts | 23.333 volts | 3 amps |

70 watts | 17.5 volts | 4 amps |

75 watts | 75 volts | 1 amp |

75 watts | 37.5 volts | 2 amps |

75 watts | 25 volts | 3 amps |

75 watts | 18.75 volts | 4 amps |

80 watts | 80 volts | 1 amp |

80 watts | 40 volts | 2 amps |

80 watts | 26.667 volts | 3 amps |

80 watts | 20 volts | 4 amps |

85 watts | 85 volts | 1 amp |

85 watts | 42.5 volts | 2 amps |

85 watts | 28.333 volts | 3 amps |

85 watts | 21.25 volts | 4 amps |

90 watts | 90 volts | 1 amp |

90 watts | 45 volts | 2 amps |

90 watts | 30 volts | 3 amps |

90 watts | 22.5 volts | 4 amps |

95 watts | 95 volts | 1 amp |

95 watts | 47.5 volts | 2 amps |

95 watts | 31.667 volts | 3 amps |

95 watts | 23.75 volts | 4 amps |

100 watts | 100 volts | 1 amp |

100 watts | 50 volts | 2 amps |

100 watts | 33.333 volts | 3 amps |

100 watts | 25 volts | 4 amps |

You might also be interested in our volts to watts calculator.

## References

- Miller, C., NFPA's Electrical References,
*National Fire Protection Association*, 2004, Jones & Bartlett Learning, 67-75. https://www.google.com/books/edition/NFPA_s_Electrical_References/raUyIi7i-asC - Miller, C., Ugly’s Electrical References, 2020 Edition, 2020, Jones & Bartlett Learning, 16-23. https://books.google.com/books?id=1kS8DwAAQBAJ