data sources
CO₂ emissions: Federal Environment Agency — GHG indicators
Consumer Data Energy (VZ): Consumer Center — Information about energy costs
Official energy statistics (Destatis): Federal Statistical Office — Energy consumption of private households
Electricity prices are rising – and many households are looking for ways to lower their costs and live more sustainably. Whether you live alone or with family: First, understand your electricity consumption to save effectively. In this guide, you'll learn how to correctly use an Energy Savings Calculator (also known as an electricity cost calculator), how costs per appliance are calculated, get practical saving tips, fact checks, and answers to frequently asked questions. This is how you take control of your electricity consumption!
An Energy Savings Calculator (also electricity cost calculator) is an interactive tool that allows you to easily estimate, analyze, and optimize your household electricity consumption. Whether you want to calculate electricity consumption for 2 people, a 4-person household, or a single appliance – the calculator provides you with individual insights for every situation.
Here's how to use the Ostrom Energy Savings Calculator for accurate results:
1. Enter Household Data
Number of people: Select how many people live in the household (e.g., 1, 2, 3, or 4+).
Apartment size: Enter the square meter (sqm) size of your apartment or house.
Region: Some calculators ask for your location to adjust average values.
2. Select Appliances
Appliance list: Choose from typical appliances (e.g., refrigerator, washing machine, dryer, dishwasher, oven, coffee machine, microwave, kettle, toaster, vacuum cleaner, hairdryer, iron, laptop, desktop, gaming PC, console, smartphone, tablet, Wi-Fi router, fan heater, wallbox, etc.).
Own appliances: Add other appliances manually.
3. Enter Usage Habits
Usage duration: Specify how many hours per day/week the appliance runs.
Power: Enter the wattage or select typical values.
Efficiency: If possible, enter the energy efficiency class (e.g., A++, A+, B).
4. Check Consumption
Total kWh consumption: The calculator sums up the estimated consumption of all appliances in kWh per month/year.
Costs: Your monthly and annual costs are calculated using your electricity price (€/kWh).
5. Discover Savings Potential
Run scenarios: Adjust settings (e.g., more efficient appliances, less standby) and see how consumption and costs change.
Compare with average: See how your household compares to similar households.
6. Receive Individual Tips
Context-based tips: The calculator gives you saving tips tailored to your appliances and usage (e.g., special tips for EV owners).
Understanding how the calculator computes costs per appliance helps you save effectively. The standard formula isAppliance Costs per Period = (Wattage × Usage Hours × Days) / 1000 × Electricity Price
A 2000-watt fan heater runs for 2 hours a day, 30 days a month, electricity price 0,30 €/kWh(2000 × 2 × 30) / 1000 × 0,30 = 120 kWh × 0,30 = 36 €/month
Refrigerator: Runs 24/7, but often cycles off. Typical consumption: approx. 150 kWh/year (efficient).
Washing Machine: Wattage × runtime × cycles per week/month.
Dryer: High power, short runtime, used infrequently.
Dishwasher: Similar to washing machine, note eco programs.
Oven/Stove: Wattage × cooking time per week.
Coffee machine, kettle, toaster: Short but high power – estimate consumption based on frequency.
Filter coffee machines: Relatively low consumption per brew, but warming plates can be energy hogs.
Pod/capsule machines: Fast, but often higher standby consumption and waste production.
Fully automatic machines: Convenient, but more complex and can also consume a lot in standby; regular descaling is important for efficiency.
Laptop/Desktop/Gaming PC: Power varies greatly – from economical laptops (15-60 watts) to energy-intensive gaming PCs (200-500 watts, peaks up to 1000W with high-end graphics cards and multiple monitors). Consumption also heavily depends on usage duration, running applications (Office vs. Gaming vs. Video Editing), and power settings.
Tip: Monitors account for a significant portion. Reduce brightness and activate sleep mode when not in use.
Consumer Electronics
Televisions (TVs): Modern LED TVs are relatively economical. Older plasma TVs are real energy guzzlers. Screen size and brightness settings play a major role. OLED and QLED are often more efficient than conventional LCDs of comparable size. Pay attention to standby mode consumption – many smart TVs consume power for background updates even when supposedly "off."
Game Consoles (e.g., PlayStation, Xbox): Can draw 150-200 watts or more during gameplay. Standby consumption (Instant-On features) is also relevant here.
Streaming Devices (Apple TV, Chromecast, etc.): Low individual consumption, but often permanently active.Sound Systems/Soundbars: Can contribute significantly to consumption depending on power and usage duration, especially at high volume.
Small Kitchen Appliances
Microwave: Efficient for quickly heating small amounts. Note standby consumption of the clock display.
Air Fryer: Often more energy-efficient than a large oven for smaller portions as they heat up faster and need to heat less space.
Instant Pot/Multi-cooker: Similar to air fryers, they can be more efficient for certain dishes than traditional methods.
Home Office Devices
Printer/Scanner: Laser printers consume a lot of power briefly when heating up; inkjet printers are more economical in operation. Standby consumption can be high in older models.
Additional Monitors: Each additional monitor increases electricity consumption.
Docking Stations/Hubs: Have their own, though usually small, electricity consumption.
Note: Average values help, but it's most accurate if you enter the actual wattage and usage of your devices.
Average: 1,500–2,200 kWh/year
Typical: 1 person, 60 sqm apartment
Main consumers: Refrigerator, lights, laptop, smartphone, TV, washing machine
Average: 2,200–3,000 kWh/year
Typical: 2 people, usually 70–90 sqm
Additional appliances: Dishwasher, dryer, more electronics
Average: 2,900–3,800 kWh/year
Typical: Family with a child, larger apartment or house
Average: 3,500–5,000 kWh/year
Typical: Family in a house, many appliances (multiple TVs, gaming PC, etc.)
- Apartment size
- Appliance efficiency
- Usage habits (e.g., eco mode, full loads)
- Heating type (e.g., electricity, instantaneous water heater)
- Number of appliances per person
Here are proven tips to reduce your electricity consumption and costs:
Switch off standby: Many devices draw power even when they are off. Power strips help turn everything off at once.
Use LEDs: LEDs save up to 80 % compared to incandescent bulbs and last much longer.
Wash/rinse efficiently: Always fully load the washing machine and dishwasher and use eco mode.
Optimize heating/cooling: Lowering the thermostat by 1 °C saves up to 6 % on heating costs. Use fans instead of air conditioning.
Unplug chargers: Unused chargers also draw power.
Buy efficient appliances: When buying new, always look for the highest energy efficiency classes (on the current A-G scale). Older top labels like A+++ often correspond to the new classes B or C.
Defrost freezer: Ice buildup increases consumption.
Air-dry laundry: Avoid using a tumble dryer whenever possible.
Cook smartly: Put lids on pots, choose the right-sized burner, use microwave/toaster for small portions.
Measure consumption: Use a meter or smart plug to find energy guzzlers.
Extra Tips:
- EV? Best to charge at night or during off-peak hours.
- Electric boiler/underfloor heating? Control with a timer to avoid unnecessary heating.
- Use time-variable tariffs: Run the washing machine, dishwasher, or EV during off-peak hours.
- Replace old appliances: A new refrigerator of the highest efficiency classes (e.g., class A or B on the current scale) saves hundreds of kWh per year compared to an old appliance.
- Use Smart Home: Reduce standby consumption with smart plugs and timers.
- Compare providers: Check tariffs with an electricity cost calculator and switch.
- Install a solar system: Self-generation makes you more independent.
- Insulate your apartment/house: Good insulation saves heating and cooling electricity.
- Check electricity consumption regularly: This way, you'll always find new savings potential.
Use air conditioning wisely: Don't set the temperature too low (e.g., 24-25°C is often sufficient). Every degree cooler significantly increases consumption. Regular maintenance (filter cleaning) is important.
Fans instead of air conditioning: Ceiling or pedestal fans consume significantly less electricity than air conditioners and can provide pleasant cooling.
Use sun protection cleverly: Keep curtains, blinds, or shutters closed on the sunny side during the day to reduce room heating.
Ventilate at night: Use the cooler night temperatures for cross-ventilation to cool down the apartment.
Cooking and baking: Shift energy-intensive cooking processes to the cooler morning or evening hours if possible to avoid additional heat generation. Use the outdoor grill more often, if available.
Optimize cooling appliances: Ensure good ventilation for the refrigerator and freezer and do not put warm food inside.
Heat and ventilate correctly:
Intermittent ventilation instead of continuous tilting: Open windows completely for 5-10 minutes instead of leaving them tilted for hours. This ensures air exchange without massive heat loss.
Do not obstruct radiators: Furniture or curtains in front of radiators prevent efficient heat distribution.
Adjust room temperature: Not all rooms need to be heated equally. Lower temperatures are often sufficient in the bedroom. Programmable thermostats help.
Additional heaters (fan heaters): Use only selectively and for short periods, as they can consume a lot of electricity. They are not an efficient permanent solution.
Lighting in winter: Since it gets dark earlier, lights are on longer. Consistent use of LEDs and motion detectors in hallways or basements can save here.
Humidifiers: Dry heating air can be unpleasant. Pay attention to the energy consumption when buying humidifiers.
Christmas lighting: Opt for LED light chains and use timers.
An electricity bill can seem complex at first glance. If you understand the individual items, you'll see better where you can make changes:
Energy Price (Cent/kWh): This is the price you pay for each kilowatt-hour of electricity consumed. Your savings measures have a direct impact here.
Basic Fee (€/Month or €/Year): A fixed fee that your energy provider charges for supplying electricity, meters, billing, etc. – regardless of your consumption. Switching to a provider with a low basic fee can be worthwhile for low consumption.
Grid Usage Fees: Fees for using the electricity grid, which go to the grid operator. These are included in the energy price or as a separate item. Their amount varies regionally.
Metering Point Operation Fee: Costs for the installation, operation, and maintenance of your electricity meter (conventional or modern/smart).
Taxes and Levies: A significant part of your bill consists of government charges:
Electricity Tax (Energy Tax): A consumption tax.
VAT (Value Added Tax): On all price components.
Concession Levy: A fee that energy suppliers pay to municipalities for the right to use public ways for lines.
Other Surcharges (variable): In the past, there were surcharges like the EEG surcharge (for promoting renewable energies) or the CHP surcharge (for promoting combined heat and power plants). Some have been abolished or greatly reduced but may return or be replaced by new ones. Check your bill for current items.
Tip: Many electricity providers offer online portals or apps where you can view your consumption and costs in detail and often compare them with previous year's values or average households. Use these tools!
Myth 1: Standby doesn't matter.
Fact: Standby can account for up to 10 % of consumption. Always switch off or unplug!
Myth 2: Old appliances are just as efficient.
Fact: Modern appliances are much more economical. A refrigerator from the 1990s can easily consume several hundred kWh more per year than a new, highly efficient model.
Myth 3: LEDs are not worth it.
Fact: LEDs save up to 80 % and pay for themselves quickly.
Myth 4: Cold washing doesn't get clothes clean.
Fact: Modern detergents clean well at 30 °C and save energy.
Myth 5: Small appliances don't matter.
Fact: Many small energy guzzlers add up – especially in large households.
Myth 6: Measuring electricity consumption is too complicated.
Fact: With calculators and smart plugs, it's very easy today.
Electricity Consumption: Amount of electricity you use
Electricity Costs: What you pay for it
kWh (Kilowatt-hour): Unit of measurement for energy
Household: Your apartment or house
Appliances: Electrical devices
Watt: Unit of measurement for power
Energy Guzzler: Appliances with high consumption
Tariff: Electricity contract
Standby: Electricity consumption in idle mode
How much electricity does a 2-person household consume?
On average 2,200–3,000 kWh/year – depending on apartment size, appliances, and usage.
How do I use an electricity cost calculator for tariff comparison?
Simply enter your annual consumption and compare offers. Switching often saves several hundred Euros per year.
How much electricity does a 4-person household need?
Usually 3,500–5,000 kWh/year – depending on size, appliances, and heating.
How do I calculate the consumption of an appliance?
Formula: (Watt × Hours/Day × Days/Month) / 1000 = kWh/Month. Multiply by your electricity price.
Is my consumption normal?
Compare with average values for your household type (1, 2, 3, or 4 people).
How much does an instantaneous water heater consume?
A typical electronic instantaneous water heater for a bath or shower has a connected load of 18 to 27 kilowatts (18,000–27,000 watts). Due to this high power, it is one of the largest potential electricity consumers in the household, even if it only draws power when needed. Total consumption depends heavily on usage duration.
How do I save electricity in a home office or with a gaming PC?
Activate energy-saving mode, turn off devices completely, and use efficient monitors/peripherals.
How much does a 1-person household consume?
Approx. 1,500–2,200 kWh/year. Unplugging devices and using efficient appliances helps.
What do a dryer, oven, or dishwasher cost?
See the appliance chapter above – simply calculate with the Energy Savings Calculator.
What is the difference between electricity consumption and electricity costs?
Electricity consumption = quantity (kWh), electricity costs = price (Euro).
How do I calculate consumption for my apartment (e.g., 2 people, 120 sqm)?
Use the calculator, enter apartment size and appliances. Larger apartments usually need more electricity.
What are the biggest energy guzzlers?
Heating, dryers, old refrigerators/freezers, standby devices.
How do I save electricity with an instantaneous water heater or electric heating?
Use timers, lower the temperature, insulate pipes and rooms.
How much more does an EV consume?
Approx. 2,700 kWh per year (at 15,000 km/year and 0.18 kWh/km) in addition to the household.
How do I keep an eye on my consumption?
Use a Smart Meter or regularly use the calculator.
How much does switching to LED save?
Up to 80 % on lighting consumption.
Why is my bill high despite efficient appliances?
Hidden energy guzzlers (old chargers, routers, standby) and inefficient heating/cooling are common reasons.
Ready to take control and save money? Try our free Energy Savings Calculator now! Simply enter your household data and appliances and see how much you can save monthly.
Start now – with the Ostrom Energy Savings Calculator!