What is a kilowatt and a kilowatt hour?
The easiest way to explain the concepts of kilowatt and kilowatt hour (kilowattimme) is to start by looking at what “power” and “energy” entail.
Power and energy
“Power” refers to the amount of electrical energy that a given device uses or produces at a given moment. Power is measured in watts (W). The more power a device uses, the more energy is required to make it work.
Energy is calculated as “power x time” and measured in watt hours (Wh). If you want to know how much energy is consumed when you use a certain device, simply multiply the power by the amount of time you use it.
Kilowatt and kilowatt hour
A kilowatt means “a thousand watts”. Energy is usually measured in kilowatt hours (kWh), which is another name for “thousand watt hours”. On your electricity bills, you will usually see “kilowatt hours” as the measurement used to show how much electricity you have consumed.
Example calculation
If, for example, you have a dishwasher with a power rating of 1,500 watts, which you use for two hours, this produces a figure of 3,000 watt hours, or 3 kilowatt hours.
How much can a kWh be used for?
Precisely how much use you can make of a kilowatt hour (kWh) does vary. Here we have collected a number of examples of approximately how much a single kilowatt hour (kWh) covers for the normal electrical devices you may have in your home.
| Example | Wattage | Time |
| Advent candelabra, LED | 0,7 W | 1,428 h |
| Filament bulb | 40 W | 25 h |
| LED light | 1 W | 1,000 h |
| String of lights | 10 W | 100 h |
| String of lights | 30 W | 33 h |
| Low-energy light | 7 W | 143 h |
| Example | Wattage | Time |
| Air fryer | 1,200-2,250 W | 25-50 min |
| Dishwasher | 1,000 W | 1 h |
| Electric mixer | 500 W | 2 h |
| Fan (for cooker, including lighting) | 200 W | 5 h |
| Freezer, class A++ | 31 W | 32 h |
| Coffe maker | 1,500 W | 40 min |
| Refrigerator, A++ | 13 W | 77 h |
| Microwave oven (full power) | 1,000 W | 1 h |
| Toaster | 1,000 W | 1 h |
| Cooking range, induction (one zone on) | 3,000 W | 20 min |
| Cooking range, induction (max. power, all zones on) | 7,350 W | 8 min |
| Cooking range, rapid zone | 1,500 W | 40 min |
| Cooking range, frying zone | 2,000 W | 30 min |
| Oven | 2,300 W | 26 min |
| Electric kettle | 2,200W | 27 min |
| Example | Wattage | Time |
| Shower | 5,000 W | 12 min |
| Shower | 1,000 W | 60 min |
| Heated towel rail | 30-200 W | 5-33 min |
| Hair dryer | 2,200 W | 27 min |
| Curling tongs | 55 W | 18 h |
| Electric razor | 5 W | 200 h |
| Example | Wattage | Time |
| LED/LCD-TV (on) | 71 W | 14 h |
| Game console | 91 W | 11 h |
| Example | Wattage | Time |
| Iron | 2,200 W | 27 min |
| Drying cabinet | 1,000 W | 1 h |
| Tumble-dryer, class B | 2,000 W | 30 min |
| Washing machine (40 degrees) | 500-1,000 W | 30-60 min |
| Washing machine (60 degrees) | 2,000 W | 30 min |
| Example | Wattage | Time |
| Air conditioning (A/C) | 1,000 W | 1 h |
| Sauna | 6,000 W | 10 min |
| Vacuum cleaner | 700 W | 1,4 h |
| Computer (stationary, used for playing games) | 100 W | 10 h |
| Electric radiator | 1,000 W | 1 h |
| Electric boost for heat pump/geothermal heat | 3,000 W | 20 min |
| Underfloor heating (1 m2) | 128 W | 8 h |
| Infra-heating | 1,800 W | 33 min |
| Charging electric vehicle (10 kW) | 10,000 W | 6 min |
| Charging electric vehicle (4 kW) | 4,000 W | 15 min |
| Charging laptop | 67 W | 15 h |
| Charging smartphone | 5 W | 200 h |
| Air heat pump (normal use/use for cooling) | 500-1,200 W | 50 min-2 h |
| Engine warmer | 670 W | 1,5 h |
| Radio | 50 W | 20 h |
| Jacuzzi (3–400 kWh/year) | 500 W | 2 h |
| Sewing machine | 71 W | 14 h |
| Water heater (electric) | 3,000 W | 20 min |