Calculateur VA vers watts
Convertit la puissance apparente (VA) en puissance active (W) avec W = VA × FP. Pratique pour UPS, onduleurs et dimensionnement.
Volt-amperes from nameplate, UPS, or inverter specs.
Between 0 and 1. PF = 1 means VA equals watts.
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Table of Contents
What VA vs watts means
VA (volt-amperes) is apparent power, while watts (W) is real power that does useful work.
In AC circuits, current and voltage may be out of phase. Power factor captures this difference: PF = W ÷ VA.
So converting VA to watts is simple: W = VA × PF.
This pairs with our watts/volts/amps tools: use those when you need current or voltage from real power.
Formula
VA to watts
W = VA × PF
PF is between 0 and 1 for most loads.
Related forms
PF = W ÷ VA | VA = W ÷ PF
If PF = 1 (purely resistive assumption), VA and watts are equal.
How this links to other electrical formulas
For real AC power from volts and amps: W = V × I × PF (single-phase) and W = √3 × VL-L × I × PF (balanced three-phase, line-to-line).
Quick Reference Table
| VA | PF | Watts | Typical load |
|---|---|---|---|
| 100 VA | 1.0 | 100 W | Resistive heater estimate |
| 150 VA | 0.8 | 120 W | Small adapter / mixed load |
| 1000 VA | 0.9 | 900 W | UPS rated at PF 0.9 |
| 2000 VA | 0.85 | 1700 W | Motor-heavy load |
FAQ
Normally no for AC loads with standard definitions; W ≤ VA because PF is typically ≤ 1.
Check the device nameplate/spec sheet. For rough estimates, many electronic loads sit around 0.8–0.95.
VA is mainly an AC concept. For DC, power is simply W = V × I.
This tool starts from apparent power (VA). Volts-to-watts starts from voltage and current or resistance.