Watts to Volts Calculator

Reviewed by the ElectricalConverters editorial team Last updated July 2026 Estimates only — how we check

Calculate voltage from watts and amps or watts and resistance.

Watts (W)

Current (A)

Circuit Type

Watts (W)

Resistance (Ω)

RESULT — VOLTAGE

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Choose a calculation mode and enter values.

How do you convert watts to volts?

Divide watts by amps: volts = watts ÷ amps. A 60 W device drawing 5 A runs at 60 ÷ 5 = 12 V. If you know resistance instead, use V = √(W × R): 60 W across 8 Ω gives √(60 × 8) = √480 ≈ 21.9 V.

Watts to Volts Conversion Table (V = W ÷ A)

Power	at 2 A	at 5 A	at 10 A	at 15 A
100 W	50.0 V	20.0 V	10.0 V	6.67 V
500 W	250 V	100 V	50.0 V	33.3 V
1000 W	500 V	200 V	100 V	66.7 V
1500 W	750 V	300 V	150 V	100 V
2000 W	1000 V	400 V	200 V	133 V

Watts to Volts Formulas

DC (using current)

V = W ÷ A

For DC circuits, voltage is simply power divided by current. Example: 500 W at 4.17 A to 500 ÷ 4.17 = 119.9 V (≈ 120 V).

AC single-phase (using current + power factor)

V = W ÷ (A × PF)

In an AC single-phase circuit, the power factor must be accounted for. Example: 500 W at 4.17 A, PF 0.9 to 500 ÷ (4.17 × 0.9) = 133.2 V.

Using resistance (Ohm's Law)

V = √(W × R)

Derived from P = V²÷R to V² = P×R to V = √(P×R). Works for DC and purely resistive AC circuits. Example: 200 W at 72 Ω to √(200 × 72) = √14,400 = 120 V.

Watts to Volts Reference Table — DC (using current)

Watts	1 A	2 A	5 A	10 A	15 A	20 A
60 W	60 V	30 V	12 V	6 V	4 V	3 V
100 W	100 V	50 V	20 V	10 V	6.6667 V	5 V
200 W	200 V	100 V	40 V	20 V	13.3333 V	10 V
500 W	500 V	250 V	100 V	50 V	33.3333 V	25 V
1000 W	1000 V	500 V	200 V	100 V	66.6667 V	50 V
1500 W	1500 V	750 V	300 V	150 V	100 V	75 V
2000 W	2000 V	1000 V	400 V	200 V	133.3333 V	100 V

Watts to Volts Using Resistance (Ω)

Watts	10 Ω	50 Ω	100 Ω	144 Ω	500 Ω
10 W	10 V	22.3607 V	31.6228 V	37.9473 V	70.7107 V
25 W	15.8114 V	35.3553 V	50 V	60 V	111.8034 V
60 W	24.4949 V	54.7723 V	77.4597 V	92.9516 V	173.2051 V
100 W	31.6228 V	70.7107 V	100 V	120 V	223.6068 V
500 W	70.7107 V	158.1139 V	223.6068 V	268.3282 V	500 V
1000 W	100 V	223.6068 V	316.2278 V	379.4733 V	707.1068 V

When do you need to find voltage from watts?

Sizing solar charge controllers (know panel watts and desired charge amps)
Amplifier and speaker circuits (know power rating and speaker impedance)
Checking nominal voltage of an unknown DC power source
Resistance-based voltage measurements with a multimeter (Ohm's Law Guide)

Frequently Asked Questions

How do I convert watts to volts?

Two approaches. Using current: V = W ÷ A for DC; V = W ÷ (A × PF) for AC single-phase. Using resistance (Ohm's Law): V = √(W × R). You need either the current (amps) or the resistance (ohms) — you cannot convert watts to volts from watts alone.

Can I convert watts to volts without knowing the amps?

Yes — if you know the resistance in ohms. Use V = √(W × R). For example, a 100 W load with 144 Ω resistance: V = √(100 × 144) = 120 V. If you have neither amps nor resistance, conversion is not possible.

How many volts is 60 watts at 0.5 amps?

DC: V = 60 ÷ 0.5 = 120 V. AC single-phase at PF 0.8: V = 60 ÷ (0.5 × 0.8) = 150 V.

What is the formula to convert watts to volts using resistance?

Combine Watt's Law (P = V²÷R) and Ohm's Law (V = I×R) to get V = √(P × R). This works for both DC and resistive AC circuits.