Senseible

Is your power factor costing you units?

Power factor is kWh ÷ kVAh. A bill with 2,500 kWh and 2,690 kVAh is at 0.93, so a kVAh tariff bills 190 more units than the factory used.

Type the kWh and kVAh printed on one electricity bill. Power factor is kWh divided by kVAh; on a kVAh tariff the gap between the two is billed as units you never used.

CO2 is worked out on the kWh only, at the CEA grid factor for the bill's financial year, the same factor the bill health check below uses.

Then check the rest of the bill: power factor, contract demand against recorded demand, tariff category and meter readings, each with a plain verdict, and download a one-page summary. Free, no email.

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The formula

Power factor = kWh ÷ kVAh. Extra billed units = kVAh − kWh. kg CO2 = kWh × the CEA grid factor for the bill's financial year (0.675 for FY 2025-26).

Worked example

  1. The bill shows 2,500 kWh and 2,690 kVAh for the same month.
  2. 2,500 ÷ 2,690 = 0.929 power factor.
  3. 2,690 − 2,500 = 190 units billed above use, 7.6% more.
  4. 2,500 × 0.675 = 1,688 kg CO2, at the CEA FY 2025-26 factor.

At 0.95 the same month would bill 132 extra units instead of 190.

How to use it

  1. Find kWh and kVAh for the same billing period, usually in the meter reading table.
  2. Type both.
  3. Read the power factor, the units billed above use and the CO2 of the kWh.

Questions people ask

How do I find the power factor from my electricity bill?

Divide the kWh by the kVAh for the same billing period. Many HT and large LT bills also print an average power factor; it should match this figure to two decimals.

Why is kVAh higher than kWh?

kWh is the energy that does work. kVAh also counts the reactive power that motors, transformers and welding sets draw back and forth. The lower your power factor, the wider the gap.

Which bills are charged on kVAh?

In Maharashtra, HT consumers and LT consumers above 20 kW have been billed on kVAh since April 2020. Other states set their own rules. If the energy charge line on your bill says kVAh, you are billed on it.

Does fixing my power factor cut my CO2?

Hardly. CO2 follows the kWh your machines use, and a capacitor bank leaves that almost unchanged. What it cuts is the kVAh you are billed for.

What power factor should I aim for?

0.95 or better. Senseible flags any kVAh bill below that. An electrician can size a capacitor bank for your load.