Two numbers on the same load
In AC systems, real power in watts and apparent power in volt-amperes are different quantities.
In 30 seconds
- Power factor is the ratio of real to apparent power.
- For a consuming load, 800 W at 0.8 power factor corresponds to 1,000 VA.
- With distorted waveforms, total power factor is not just the cosine of a phase angle.
Make it concrete
A UPS specification lists both W and VA. A proposed load must respect both limits; one number does not replace the other.
- 01Real power W
- 02÷ Apparent power VA
- 03Power factor
Check your understanding
Are watts and volt-amperes always numerically identical?
- Power factor is the ratio of real to apparent power.
- For a consuming load, 800 W at 0.8 power factor corresponds to 1,000 VA.
- With distorted waveforms, total power factor is not just the cosine of a phase angle.
Go to the source
Sources reviewed: 13.09.2026