The power consumption of an appliance is calculated based on the number of watts and the duration of operation in hours. To calculate the electricity costs of the appliance, the result in kilowatts per hour (kWh) is multiplied by the electricity price.
Calculator
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Use calculator:
- Enter the number of watts into the calculator.
- Enter the duration of device operation in hours.
- Optional: Enter the electricity price per kWh.
- Click on
Formulas for calculation:
Number of watts * duration in hours = power consumption
Power consumption * electricity price = electricity costs
Table
Power consumption per number of watts for one hour of operation:
| Number of watts | Power consumption (for 1 hour of operation) |
|---|---|
| 7 watts | 0.007 kWh |
| 10 watts | 0.01 kWh |
| 23 watts | 0.023 kWh |
| 27 watts | 0.027 kWh |
| 40 watts | 0.04 kWh |
| 60 watts | 0.06 kWh |
| 100 watts | 0.1 kWh |
How exactly is electricity consumption actually calculated? How can you save electricity? Which appliances are the biggest power guzzlers? There are many questions and points to consider when it comes to electricity consumption.
How is electricity consumption calculated?
When we talk about electricity consumption, we usually mean electrical work. It indicates how much electrical energy is converted into other forms of energy, such as light or heat. This means that every time a light bulb is operated with electricity and produces light, electrical work is performed. This quantity is measured in watts per hour (Wh) or kilowatts per hour (kWh).
To demonstrate the whole thing using a concrete example, let's imagine an LED lamp that consumes 6 watts. If it is operated for 1,000 hours a year, this results in a power consumption of 6,000 watts, which corresponds to 6 kilowatts. To obtain the price for this amount of electricity consumed, simply multiply the electricity price by the 6 kilowatts. With an exemplary price of 25 cents/kWh, this results in 6 × €0.25, i.e. €1.50.
If you want to calculate your total electricity consumption, simply repeat this procedure for each appliance used in the household. The consumption of the individual appliances can be found on the packaging or, in the case of larger machines, directly on them. Fortunately for us, there are electricity meters that do this work for us, so in the end we only have to multiply the total consumption by the price per kilowatt.
How to reduce electricity consumption?
Now that you know how to calculate your electricity consumption, you are probably wondering how you can reduce your consumption and save money. To answer this question, it makes sense to first identify the biggest electricity consumers in your household. As a general rule, appliances that generate heat require the most electricity. It is therefore not surprising that the biggest power guzzler in households is the stove. At around 5,000 watts, it consumes almost twice as much as a tumble dryer or dishwasher (3,000 watts each).
Smaller appliances such as kettles and hairdryers should not be underestimated either, as they consume 2,000 and 1,400 watts respectively. Other notable power consumers are: Washing machine (2500 W), vacuum cleaner (1200 W), microwave (1000 W) and coffee machine (900 W).
Once the biggest energy consumers have been identified, the next step is to find out how consumption can be reduced. The most obvious thing to do, of course, is to simply minimize consumption. In practice, this means switching off the lights as often as possible, not leaving the TV on unnecessarily, and so on. Using less hot water can also save a lot of electricity. Most people underestimate the amount of electricity needed to heat water. Saving hot water is easy: take a shower more often instead of a full bath and when you shower, you should wash your body for a shorter time and, above all, at a colder temperature, which is also good for your health.
The energy efficiency classes
Another often underestimated method of saving electricity is to buy new appliances with a better energy efficiency rating. Of course, newer appliances cost a little more, but in some cases they can significantly reduce electricity consumption. For example, a refrigerator with energy efficiency class A consumes around 70 percent less electricity than an appliance with class A (assuming they have the same features).
How much do I consume compared to the average?
To get a better idea of your own electricity consumption and whether you still have potential to save electricity, it is worth taking a closer look at the average electricity consumption in Germany. Generally speaking, consumption in detached or semi-detached houses is higher than in apartment buildings. In addition, electricity consumption per capita decreases the more people live in a house, which is due to the fact that appliances such as refrigerators can be used collectively.
It makes sense to divide the analysis into single and four-person households, as well as single-family or two-family houses and multi-family houses.
Single households in detached or semi-detached houses consume an average of 2,300 kWh; if the hot water is heated electrically, this figure rises to 2,800 kWh per year. This corresponds to €690 and €840 respectively. According to Stromspiegel, there is still an opportunity to save up to €70 on fridges and freezers and €115 by avoiding standby mode.
Single-person households in apartment buildings consume between 1,400 kWh and 1,900 kWh (with electric water heating). This corresponds to average electricity costs of €555 per year. Here too, it is possible to reduce consumption by up to €370 by saving.
A four-person household in a detached or semi-detached house consumes an average of around 5,000 kWh per year, which corresponds to a price of €1,465. Saving energy can reduce costs to €1,250.
If four people live in an apartment building, consumption is 4,400 kWh, or €1,170 per year. With an economical lifestyle, the costs can be reduced to €745 per year.