Electricity • Costs • Consumption

Calculate Electricity Costs

Calculate electricity consumption and costs from power, runtime and unit price.

Electricity • Costs • Consumption

Calculate electricity consumption and costs from power, runtime and unit price.

Calculation Values

Note: This calculator provides a technical estimate for guidance only. For electrical installations, standards, protective measures, installation method, ambient temperature, grouping, protective devices and manufacturer specifications must also be checked.

Formula Used

kWh = (Watts ÷ 1000) × Hours × Days

Costs = kWh × Price per kWh

The calculator converts watts to kilowatts and uses that to calculate the energy consumption in kWh.

Frequently Asked Questions

Are base fees included?

No. The calculator only considers the unit price per kWh, not monthly base fees.

What does kWh mean?

kWh stands for kilowatt-hour and describes energy consumption over a given time.

How accurate is the calculator?

The calculation is mathematically precise, provided power, runtime and electricity price are entered correctly.

Practical guidance

Estimate energy cost from a realistic usage profile

Rated power, operating time and energy price produce a transparent estimate only if the device actually draws that power for the stated time.

Input values explained

Power in watts: Use the electrical active power drawn by the load. A nameplate, data sheet or power meter is more reliable than an estimate.
Operating time: Enter the actual operating time in the period considered. Thermostatically controlled or cycling devices rarely run continuously at rated power.
Number of days: This value extrapolates an identical daily usage pattern. Seasonal and weekday differences are not included automatically.
Energy price: Use your tariff's energy charge in cents per kWh. Standing charges, metering fees and future price changes are excluded.

Example: 1,000 W for five hours a day

A device runs for five hours on 30 days at a constant 1,000 W, with energy priced at €0.35/kWh.

1 kW × 5 h × 30 = 150 kWh; 150 × €0.35 = €52.50

Estimated energy cost is €52.50. The tariff's standing charge is not caused by this single appliance.

Why actual cost can differ

Heating, refrigeration and machinery often cycle. A meter reading over a representative period is better than rated power times time.

Calculation limits

Standing charges, tariff tiers and future price changes are excluded.
Standby, partial load and seasonal operating hours must be reflected in the inputs.