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Electricity Cost Calculator

Calculate electricity costs for appliances, households, standby consumption or annual usage. With electricity price, kWh, watts, base fee, calculation steps and examples.

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Inputs

Enter values

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Appliance CostsHow much does an appliance cost per day, month or year?

Select appliance (optional)

Select an appliance to use its typical wattage.

Wattage

watts

How many watts does your appliance use? Usually found on the nameplate.

Hours per day

hours

How many hours per day does the appliance run?

Electricity price

cents/kWh

Example value. Find your price on your electricity bill.

Load example

For illustration only – your own calculation is what counts.

Explanation

How Electricity Cost Calculator works

The electricity cost calculator computes the energy consumption and costs of an electrical appliance or an entire household. It offers five modes: appliance costs, consumption costs, annual costs, price comparison and standby costs.

Unit Price vs. Base Fee

Consumption per dayConsumption (kWh/day) = Wattage (W) / 1000 x Hours per day

The wattage is converted from watts to kilowatts and multiplied by the daily operating time.

Cost per yearCost (currency/year) = Consumption (kWh/day) x 365 x Electricity price (currency/kWh)

The daily consumption is extrapolated to a year and multiplied by the electricity price.

Standby Consumption

The unit price (cents/kWh) is charged per kilowatt-hour consumed. The base fee is a monthly flat charge. When comparing prices, both components must be considered to calculate the actual savings.

Confusing Watts and Kilowatt-Hours

Standby mode treats the entered wattage as constant for the entered standby hours; active use is not added automatically.

Knowledge

Understanding Electricity Consumption and Costs

Fundamentals for calculating energy consumption and electricity costs for household appliances.

The electricity consumption of an appliance depends on its power draw (watts) and operating time. The unit kilowatt-hour (kWh) describes the energy consumed: 1 kWh = 1000 watts operated for 1 hour.

The electricity price consists of a unit price (cents/kWh) and a base fee (euros/month).
Continuous operation (24/7) is typical for routers, refrigerators and servers.
Standby consumption adds up to significant costs over the year.
Switching tariffs often pays off even with just a few cents difference per kWh.

Practice

Practical examples

For illustration only – your own calculation is what counts.

LED Lamp

Calculate the electricity costs for a 10-watt LED lamp used 5 hours per day.

Result: The LED lamp costs approximately 7.30 euros per year at 5 hours of daily use.

TV in the Evening

Calculate the electricity costs for a 120-watt TV used 3 hours and 30 minutes per day.

Result: The TV consumes 0.42 kWh per day and causes approximately 61.32 euros in electricity costs per year.

Desktop PC (Workdays)

Calculate the electricity costs for a 350-watt desktop PC used 8 hours on 5 days per week.

Result: The model gives 730 kWh and 292.00 euros per year at 8 hours on 5 days per week.

Refrigerator (Continuous Operation)

Calculate the electricity costs for a 100-watt refrigerator running continuously (24h/day, 7 days/week).

Result: At a constant assumed 100 watts, continuous operation gives 876 kWh and 350.40 euros per year.

Annual Consumption 3500 kWh

Calculate the costs for 3500 kWh consumption at 40 cents/kWh.

Result: 3500 kWh at 40 cents/kWh costs a total of 1,400.00 euros.

Annual Costs with Base Fee

Calculate the annual costs at 250 kWh/month, 38 cents/kWh and 12 euros base fee per month.

Result: At 250 kWh per month, annual costs amount to 1,284.00 euros (including base fee).

Electricity Price Comparison

Compare two tariffs: 3500 kWh consumption, old price 42 cents, new price 36 cents.

Result: By switching, you save 210.00 euros per year.

Standby Costs TV

Calculate the standby costs for a TV with 0.5 watts in standby (20 hours per day).

Result: The TV causes approximately 1.46 euros per year in standby.

Standby Costs Router

Calculate the standby costs for an 8-watt router that is in standby 24 hours per day.

Result: The router causes approximately 28.03 euros per year in continuous standby costs.

Notes

Common mistakes

Users enter the power in kW instead of watts or confuse power (watts) with energy (kWh). An appliance with 2000 watts is entered as 2000 kWh.
Watts is power (instantaneous consumption), kWh is energy (power × time). 2000 watts for 1 hour equals 2 kWh. Enter the power in watts in the calculator.
Standby consumption ignored
Only active usage time is calculated, even though many appliances continue running in standby. Routers, TVs and game consoles consume power 24 hours a day.
Calculate standby mode separately: standby power × standby hours per day. For a total balance, add both values together.
Cents and euros confused for electricity price
The electricity price is entered in euros instead of cents (e.g., 0.40 instead of 40). The result is then too low by a factor of 100.
The calculator expects the electricity price in cents per kWh. Take the value directly from your electricity bill (e.g., 40 cents/kWh).
Rated power assumed as average consumption
The maximum power stated on the nameplate is used for calculation, even though the appliance consumes less during normal operation.
The rated power is not necessarily the average power consumption. For varying or cyclical loads, use a measured average power or documented energy consumption as input.
The calculator uses only the entered fixed electricity price. The unit price, base charge and other terms of the specific contract are decisive.

FAQ

Frequently asked questions

How do you calculate electricity costs for an appliance?

The wattage is converted to kilowatts (watts / 1000), multiplied by the usage time in hours, yielding the consumption in kWh. Multiplied by the electricity price (currency/kWh), this gives the costs.

Which electricity price should I enter?

Use the unit price from your contract or bill. Preset amounts and examples are calculation values, not current average prices.

How do I calculate standby costs?

Enter the measured or documented standby wattage, daily standby hours and your electricity price. The wattage is treated as constant over that period.

What is the difference between unit price and base fee?

The unit price is charged per kilowatt-hour consumed (cents/kWh). The base fee is a fixed monthly charge regardless of consumption. Together they make up your electricity costs.

What does price comparison include?

It compares unit prices and optional base charges for the same annual use. Bonuses, tiers, dynamic prices and other contract terms are excluded.

How do I calculate the annual consumption of an appliance?

Annual consumption = Wattage (kW) x Hours per day x 365 x (Days per week / 7). For a 100-watt appliance at 8 hours daily: 0.1 kW x 8 h x 365 = 292 kWh per year.

How does usage on only certain days affect the result?

If an appliance is not used every day, specifying the days per week reduces the annual consumption proportionally. At 5 out of 7 days, costs decrease by about 29 percent.

How accurate is the calculation?

The calculation is a theoretical reference value. Actual consumption depends on efficiency, standby consumption, inrush currents and usage patterns. For an exact measurement, a power meter is necessary.

Limits

Limitations

Dynamic electricity tariffs with fluctuating hourly prices are not supported. The calculator works with a fixed price.
The calculated values are theoretical reference values. Inrush currents, standby, variable loads and efficiency factors can alter actual consumption.
Self-consumption from photovoltaic systems or feed-in is not considered.
The Bundesnetzagentur explains the unit cents per kilowatt-hour and the calculation of the billing amount from consumption, unit price and base charge.

Sources

Sources and references

Arbeitspreis (Energie)Bundesnetzagentur
Annual report on the state of energy markets. Contains average prices, consumption data and competition analyses for electricity and gas.
View sourceRetrieved: 07/30/2026 · Verified on: 07/30/2026
Monitoringbericht EnergieBundesnetzagentur
Official regulation text on contract terms and billing in basic electricity supply; the specific contract and billing remain authoritative.
View sourceRetrieved: 07/30/2026 · Verified on: 07/30/2026
StromgrundversorgungsverordnungBundesministerium der Justiz und für Verbraucherschutz
Official statistics on energy prices in Germany. Long-term time series of electricity prices for various consumer groups.
View sourceRetrieved: 07/30/2026 · Verified on: 07/30/2026 · Primary source
Energiepreise für HaushalteStatistisches Bundesamt (Destatis)
Electricity cost calculation with user-entered price; examples are explicitly not current average prices.
View sourceRetrieved: 07/30/2026 · Verified on: 07/30/2026 · Primary source

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