How to use
Choose a period and enter your own energy tariff. Add appliances using the input method that matches the evidence: watts and active time, kWh per day or year, or kWh per cycle with cycles per week. Enter quantities for identical appliances and optionally include standby power where supported.
Country settings help select currency, number format and charge wording; they do not load a current tariff or convert prices. Optional fixed charges can be recurring per day, month or year, or a one-off amount for the selected period. A second scenario can compare a different appliance or use pattern.
Calculation method
For power-based input, active energy is watts / 1,000 × active hours, adjusted for the entered weekly use pattern and period. Measured energy input scales a daily or annual figure to the period. Cycle input multiplies energy per cycle by the number of cycles and scales the weekly pattern.
Energy cost uses total unrounded kWh multiplied by the tariff. Applicable recurring charges are added to the relevant projections. A one-off period charge appears only in the selected-period total; the other cards then describe usage cost. Splitting identical appliances between rows does not create artificial savings through premature rounding.
Worked example
A 1,000 W appliance used one hour every day consumes 1 kWh per day and 30 kWh in thirty days. At 0.20 per kWh, usage costs 6.00. Adding a recurring 0.50 daily charge makes the thirty-day total 21.00. As a one-off selected-period charge of 15.00, that total is still 21.00, but the other periods’ cards exclude it.
Choose realistic input data
A rated maximum wattage is not automatically average consumption for a cycling refrigerator or air conditioner. Use measured energy or suitable label data when available. A figure per hundred cycles must be divided by one hundred before entering kWh per cycle.
This estimate does not reproduce every bill’s time-of-use, tiered, demand, tax or minimum-charge structure. Check the percentage calculator for a relative change or the 3D printing cost calculator for energy within a print-cost model.
For the measurement and planning details, read appliance electricity: choosing watts, kwh or cycle data.