Kilowatt is 1000 watt units.
Kilowatts to Attowatts Converter — kW to aW
Convert Kilowatt (kW) to Attowatt (aW) using the exact conversion factor (1 kilowatt = 1e+21 attowatt). See the formula, worked examples, conversion table, history, and common uses.
Kilowatts to Attowatts converter
Converter
Power Converter
Convert watts, horsepower, refrigeration tons, BTU per hour, and engineering power units.
Context values
Some unit families need one extra value for a physically accurate result.
Attowatt is 1e-18 watt units.
Result = input x 1000 / 1e-18.
Power uses the watt as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Kilowatts to Attowatts
Kilowatt and Attowatt both describe power output, and the conversion is a routine part of comparing an engine or motor's spec sheet across countries that use different power units. Kilowatt is most often used for electric vehicle motor power ratings (alongside horsepower).
Formula
attowatts = kilowatts × 1e+21
This factor comes from each unit's defined relationship to the category's base unit: 1 kilowatt equals 1000 base units, and 1 attowatt equals 1e-18 base units, so dividing one by the other gives the direct kilowatt-to-attowatt factor of 1e+21.
Simple example
1 kW × 1e+21 = 1e+21 aW
1 kilowatt = 1e+21 attowatts.
Real-world example
100 kW × 1e+21 = 1e+23 aW
100 kilowatts = 1e+23 attowatts.
Conversion table
| Kilowatt (kW) | Attowatt (aW) |
|---|---|
| 1 kW | 1e+21 aW |
| 10 kW | 1e+22 aW |
| 100 kW | 1e+23 aW |
| 500 kW | 5e+23 aW |
| 1,000 kW | 1e+24 aW |
| 5,000 kW | 5e+24 aW |
Reverse conversion: Attowatt to Kilowatt
1e+21 aW × 1e-21 = 1 kW
1e+21 attowatts = 1 kilowatts.
kilowatts = attowatts × 1e-21
For a page dedicated to this direction, see Attowatt to Kilowatt.
Understanding the Kilowatt
Kilowatt (kW) measures power. A kilowatt is 1,000 watts. It is classified as a SI derived (metric prefix) unit.
Where it's used: Standard power unit worldwide for larger appliances, vehicles, and electrical systems
Uses of the Kilowatt today
- Electric vehicle motor power ratings (alongside horsepower)
- Household electrical system and generator capacity
- Industrial motor and equipment power ratings
History of the Kilowatt
The kilowatt follows directly from the watt via the standard SI 'kilo-' prefix, becoming especially prominent with the growth of electrical power generation and distribution in the late 19th and 20th centuries.
Historical origin. Kilowatt was not the invention of a single named person; it developed through the process described above.
Understanding the Attowatt (aW)
Attowatt is 1e-18 watt units.
Kilowatt — sources
- BIPM SI Brochure — SI prefixes — Defines 'kilo-' as the prefix for 10³.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many attowatts are in 1 kilowatt?
1 kilowatt equals 1e+21 attowatts, using the exact defined conversion factor rather than an estimate.
How do I convert kilowatt to attowatt?
Multiply the kilowatt value by 1e+21. The converter above does this instantly to whatever precision you set.
How do I convert attowatt back to kilowatt?
Use the reverse factor: 1 attowatt equals 1e-21 kilowatts. You can also use the swap control in the converter above to flip the direction instantly.
What is a kilowatt?
Kilowatt (kW) measures power. A kilowatt is 1,000 watts. It is classified as a SI derived (metric prefix) unit.
What is a attowatt?
Attowatt (aW) is a unit of power.
Is the kilowatt to attowatt conversion exact?
Yes. Both kilowatt and attowatt are defined by fixed standards rather than physical artifacts, so the factor of 1e+21 used above is exact to as many digits as you choose to display.
Where is the kilowatt still used today?
Standard power unit worldwide for larger appliances, vehicles, and electrical systems