Reactive Power Converter
Convert reactive power between var, kvar and Mvar - handy for power-factor correction and electrical engineering calculations.
About the Reactive Power Converter
This tool converts reactive power between var (volt-amperes reactive), kilovar (kvar) and megavar (Mvar). Reactive power is the portion of AC power that oscillates between the source and inductive or capacitive loads without doing net work, so it is measured in var rather than watts.
How to use it
- Enter the value you have into its field, for example a capacitor bank rated in kvar.
- Read the equivalent in var or Mvar.
- Convert in either direction when a grid document uses a different prefix.
The prefixes step by 1000: 1 kvar is 1000 var and 1 Mvar is 1000 kvar. Reactive power matters for power-factor correction, where capacitor banks supply var to offset the reactive demand of motors and transformers, reducing the apparent power drawn from the grid. Real, reactive and apparent power form a right triangle, so they relate as S squared = P squared + Q squared, where Q is reactive power in var. This converter handles only the var units, runs in your browser, and stores nothing.
Frequently asked questions
How many var are in a kvar?
One kilovar equals 1000 var, and one megavar equals 1000 kvar or 1,000,000 var.
What is reactive power?
Reactive power is the energy that flows back and forth between the source and inductive or capacitive loads without doing useful work. It is measured in var and supports the voltage and magnetic fields in AC systems.
How does reactive power relate to real and apparent power?
They form a right triangle: apparent power S squared equals real power P squared plus reactive power Q squared. Real power is in watts, reactive in var and apparent in volt-amperes.
Why is reactive power important for the grid?
Excess reactive power lowers the power factor and increases current for the same useful work. Capacitor banks supply var locally to correct this and ease load on the network.