Electronics / Circuits
Watts to Amps Calculator: W, kW and kVA
Convert W, kW and kVA to amps or amps to power, using voltage and power factor for DC, single-phase and balanced three-phase AC.
Watts to Amps Calculator: W, kW and kVA: Find the current drawn by a known electrical load, or calculate its power from current. Choose watts for a small device, kilowatts for larger equipment, or kVA for apparent AC power. The voltage presets cover common battery and supply voltages, with a custom input for other values. DC uses current = power ÷ voltage. AC real power also needs the power factor: a lower power factor means more current for the same watts. Balanced three-phase loads use √3 times the line-to-line voltage, or three times the line-to-neutral voltage. The displayed formula changes with your choices. kVA measures apparent power and does not use a power-factor multiplier. These calculations assume a balanced steady-state load; starting current and cable ratings require separate checks. Use the Ohm's law calculator for resistance and the electricity cost calculator for running costs. Runs 100% locally in your browser with zero server file uploads.
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8.333 A
I = P / (V)Convert kW or kVA to W or VA by multiplying by 1,000 before using the formula. Three-phase results assume a balanced load.
Power and current
IEC 60050, International Electrotechnical Vocabulary, defines active power, apparent power and power factor. Basic circuit theory gives P = VI for DC and P = VI × PF for single-phase AC.
Balanced three-phase circuits
OpenStax University Physics Volume 2, alternating-current circuits, explains real power and power factor. Standard balanced three-phase circuit theory gives S = √3 × V_LL × I = 3 × V_LN × I; P = S × PF.
How to use it
- Choose DC, single-phase AC or balanced three-phase AC.
- Choose the power unit and conversion direction, then enter the amount and voltage.
- For AC real power enter the power factor; for three-phase choose line-to-line or line-to-neutral voltage.
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Frequently asked questions
Can I convert kVA to amps?
Yes. Select an AC circuit and kVA. For single-phase use I = S ÷ V; balanced three-phase uses I = S ÷ (√3 × V_LL). Multiply kVA by 1,000 to get VA.
What if my voltage is line to neutral?
Choose line to neutral for three-phase. A balanced system has V_LL = √3 × V_LN, so current is P ÷ (3 × V_LN × PF).
Can I convert amps to watts or kVA?
Choose amps to power. The same formula is rearranged to multiply current by voltage, the phase factor and, for AC watts, power factor.
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