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

Engineering Converter

Convert common stress, force, torque, power, and energy units used in engineering.

Result 1 kilowatt = 1e+21 attowatt
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From definition

Kilowatt is 1000 watt units.

To definition

Attowatt is 1e-18 watt units.

Formula

Result = input x 1000 / 1e-18.

Power units are compatible.

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About Converting Kilowatts to Attowatts

Kilowatt and Attowatt both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. 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 kW1e+21 aW
10 kW1e+22 aW
50 kW5e+22 aW
100 kW1e+23 aW
500 kW5e+23 aW
1,000 kW1e+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.
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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 engineering.

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

Why do engineering unit conventions vary so much by region and industry?

Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.