Wattage calculator
Calculate real electrical power from voltage, current and power factor for DC or AC.
Formula
DC: P = VI; 1-phase AC: P = VI × PF; balanced 3-phase: P = √3 VI × PF.
Real power ≈ (12)×(2)
How to use
- Choose DC, single-phase or balanced three-phase AC.
- Enter volts and amps; for AC use RMS values and total PF.
- Read total watts; three-phase voltage is line-to-line.
Examples
- 250 V × 5 A × 0.8 = 1,000 W for single-phase AC.
Frequently asked questions
Are watts and volt-amperes the same?
For AC, real power equals apparent power times total power factor. PF is not always cos φ with distortion.
Which three-phase voltage is used?
RMS line-to-line voltage and line current, for a balanced system; the result is total three-phase power.
Does the result size wiring?
No. This is a power calculation, not a cable, breaker or installation design.
Sources
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