Volts to Watts Calculator

Convert volts to watts by entering voltage and current. Works for DC and AC circuits with power factor support. See conversion tables for US standard voltages (120V, 240V, 208V, 480V).

V
A

POWER

1,800 W

KILOWATTS

1.8 kW

CIRCUIT TYPE

DC

FORMULA

P = V Γ— I

Volts to Watts β€” Common Conversions

Voltage5 A10 A15 A20 A
12 V60 W120 W180 W240 W
24 V120 W240 W360 W480 W
48 V240 W480 W720 W960 W
110 V550 W1,100 W1,650 W2,200 W
120 V600 W1,200 W1,800 W2,400 W
208 V1,040 W2,080 W3,120 W4,160 W
220 V1,100 W2,200 W3,300 W4,400 W
240 V1,200 W2,400 W3,600 W4,800 W
277 V1,385 W2,770 W4,155 W5,540 W
480 V2,400 W4,800 W7,200 W9,600 W

πŸ’‘ How to Convert Volts to Watts

Voltage alone doesn't tell you power β€” you also need current (amps). Converting volts to watts uses the same Watt's Law formula: Power = Voltage Γ— Current. This calculator lets you quickly determine the wattage for any voltage and amperage combination.

Volts to Watts Formula

DC Circuit: P = V Γ— I
Single-Phase AC: P = V Γ— I Γ— PF
Three-Phase AC: P = V Γ— I Γ— PF Γ— √3

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

Example: US Standard 120V Outlet at 15 Amps

P = 120V Γ— 15A = 1,800 watts

This is the theoretical maximum for a 15-amp, 120V circuit β€” the most common circuit type in US homes.

US Voltage Standards

Understanding US voltage standards is crucial for accurate conversions:

VoltageTypeCommon Use
12V DCDirect CurrentAutomotive, RV, solar batteries
24V DCDirect CurrentSolar systems, industrial controls
120V ACSingle-PhaseUS residential outlets (standard)
208V ACThree-PhaseUS commercial buildings
240V ACSingle/Split-PhaseUS residential (dryers, ovens, AC)
277V ACThree-PhaseUS commercial lighting
480V ACThree-PhaseUS industrial, large motors

References

  • NFPA 70 β€” National Electrical Code (NEC), 2023 Edition
  • IEEE Standard 141 (Red Book) β€” Electric Power Distribution for Industrial Plants
120V Γ— 15A = 1,800 watts β€” the max for a US standard outlet. 240V Γ— 30A = 7,200 watts β€” typical for an electric dryer circuit.

Volts to Watts Calculator FAQ

πŸ”— Related Calculators

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