Watts to kVA Calculator: The Global Standard for Power Sizing
Used by electrical engineers, facility managers, and OEMs worldwide, our watts to kva calculator ensures safe and efficient power system design.
"Potentia vera" — True power.
How the Watts to kVA Calculator Works
Core equations:
kVA = (Watts / 1000) / (PF × Efficiency)
S = P / (PF × η)
I = P / (V × PF × √3) [3-phase]
S = P / (PF × η)
I = P / (V × PF × √3) [3-phase]
Watts to kVA Calculator: Four Essential Modes
Single Phase Mode
Residential and light commercial using our watts to kva calculator.
Three Phase Mode
Industrial motors and HVAC systems.
DC to AC Mode
Solar inverters and battery systems.
UPS & Inverter Mode
Data centers and critical loads.
Watts to kVA Calculator: Power Factor Guide
| Load Type | Typical PF | kVA Multiplier |
|---|---|---|
| LED Lighting | 0.95–0.99 | 1.01–1.05 |
| Induction Motor | 0.75–0.85 | 1.18–1.33 |
| IT Equipment | 0.9–0.98 | 1.02–1.11 |
Watts to kVA Calculator: Standard Ratings
- UPS: Size at 1.25 × load (80% derating)
- Generator: 1.1–1.3 × load kVA
- Inverter: 92–96% efficiency typical
- Transformer: 100% PF at full load
- Cable: I = kVA × 1000 / (V × PF)
Pro Tips for the Watts to kVA Calculator
- Always oversize 20% for future growth
- Measure actual PF with power analyzer
- Include inrush: Motors 5–7× FLC
- Harmonics: Reduce PF by 5–10%
- Temperature: Derate 1% per 5°C above 40°C
Power Without Limits
From homes to factories, our watts to kva calculator ensures reliable electricity.
Calculate kVA