Key answer
Calculation used
Annual estimate = annual kWh × unit rate ÷ 100 + standing charge × 365 ÷ 100 + known annual fees. VAT, Climate Change Levy and variable pass-through costs are excluded unless you include them in the fees field.
How to use the result
Use annual consumption from a recent statement or bill. Check whether the supplier's rate includes the same costs as another quote. If a charge is unknown, make a note rather than entering zero and treating the estimate as complete.
Actual invoices depend on measured or estimated consumption and the contract. The result is a comparison aid, not a bill forecast or supplier offer.
Sources
Primary sources checked for this page: