W to VA Calculator
Enter real power in watts and the load power factor to calculate apparent power in VA.
Enter pure real power in watts and the load power factor. Apparent power is reported in volt-amperes; PF is required and is not assumed to be 1.
S (VA) = P (W) ÷ PF
Apparent power
A QUICK WALKTHROUGH
How to use this tool
- Enter pure real power in watts.
- Enter the load power factor greater than 0 and at most 1; it is required and is not assumed to be 1.
- Calculate and review apparent power in VA.
Formula and power definitions
Apparent power S (VA) = pure real power P (W) ÷ power factor PF. Enter real (active) power separately from apparent power; the calculator does not treat watts as VA.
Local estimate
This browser-only calculator uses the values you enter. It does not measure equipment or provide electrical safety or engineering sign-off.
GOOD TO KNOW
Common questions
Can I calculate VA from watts alone?
No. Enter the load power factor because VA = W ÷ PF.
Should I enter 80 or 0.8?
Enter 0.8 for 80%. The field accepts a decimal greater than 0 and at most 1.
Does the calculator assume PF of 1?
No. A positive power factor must be entered before it calculates.