Electricity Cost Calculator

How this calculator works

This browser-based tool helps you make a first, transparent estimate from the values you provide. Enter the figures in the fields and the result updates as you edit them. JavaScript performs the calculation on your device; the calculator does not send your salary, property, vehicle or account details to a calculation server. Keep supporting documents secure and only enter sensitive figures on a device you trust.

Formula, assumptions and limits

Estimate electricity use and appliance costs in Germany or the United Kingdom. This tool applies watts × hours × days ÷ 1,000, then multiplies kilowatt-hours by the tariff you enter.

Do not rely on a rounded estimate for a tax return, payment or legal decision. Compare it with official notices, current rate tables and professional advice where needed. Real-world outcomes may include additional reliefs, fees, rate changes or personal circumstances that a simple calculator cannot represent. Your entries are not saved and are discarded when you close the tab.

Use the output as a planning aid: verify each input, read the assumptions and adjust the figures when your circumstances differ. If an important detail is uncertain, contact the relevant authority or a qualified tax, legal or financial professional.

Before acting, check your inputs, tax year and jurisdiction. Note the assumptions used, compare the result with records and official guidance, and recalculate when rules or your circumstances change.

Estimate electricity use and appliance cost

Energy use is calculated by multiplying an appliance’s power in watts by hours used each day and the number of days, then dividing by 1,000 to convert watt-hours into kilowatt-hours. The calculator multiplies that consumption by the price per kWh you enter. It works for one device or a repeated usage pattern; for several appliances, add separate estimates or total their consumption. Use a realistic average power draw rather than assuming the maximum rating on a label is constant. Standby use, variable cycles and peak demand can make actual consumption different from a simple estimate.

The result is the consumption-based part of a bill, not a complete household invoice. Standing charges, network costs, taxes, levies, time-of-use rates and discounts may be added separately or already included in the unit price. Enter the tariff in cents per kWh for Germany or pence per kWh for the UK; the country choice controls the output currency. Compare the same billing period and the same tariff components when assessing appliances or suppliers. Where power varies substantially, a plug-in energy meter over a normal week may produce a better estimate than the appliance’s rated wattage. Keep the bill nearby so the unit price is entered consistently.

Frequently asked questions