Find the consumption and unit rate
Locate total electricity consumption in kilowatt-hours and the monetary charge applied per kWh. A bill may use words such as energy charge, unit rate, usage rate, supply rate, or consumption charge. Convert cents, pence, paise, or fils into the main currency unit before using the calculator.
Do not assign every bill charge to one appliance
Daily supply charges, meter fees, minimum charges, and some taxes do not necessarily change when an appliance uses one additional kWh. They matter to the household bill, but adding them to every appliance can double-count cost. Use the marginal energy rate for an operating decision unless the tariff makes another charge consumption-dependent.
Treat tiers and time bands explicitly
For a block tariff, use the rate that the extra usage is likely to occupy. For time-of-use service, run the appliance once at the peak rate and once at the off-peak rate. This produces a decision range rather than hiding tariff complexity inside a misleading average.
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How this page was prepared
PowerCost Lab publishes this page to help readers make a specific electricity-cost decision. Worked figures are recalculated from the inputs shown, assumptions remain visible, and market facts are separated from user-entered estimates.
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