Kilojoule is 1000 joule units.
Kilojoules to Zettajoules Converter — kJ to ZJ
Convert Kilojoule (kJ) to Zettajoule (ZJ) using the exact conversion factor (1 kilojoule = 1e-18 zettajoule). See the formula, worked examples, and conversion table.
Kilojoules to Zettajoules converter
Converter
Energy Converter
Convert joules, calories, kilowatt-hours, BTU, electronvolts, therms, and mechanical work units.
Context values
Some unit families need one extra value for a physically accurate result.
Zettajoule is 1e+21 joule units.
Result = input x 1000 / 1e+21.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Kilojoules to Zettajoules
Kilojoule and Zettajoule both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: Kilojoule is 1000 joule units, and zettajoule is 1e+21 joule units.
Formula
zettajoules = kilojoules × 1e-18
This factor comes from each unit's defined relationship to the category's base unit: 1 kilojoule equals 1000 base units, and 1 zettajoule equals 1e+21 base units, so dividing one by the other gives the direct kilojoule-to-zettajoule factor of 1e-18.
Simple example
1 kJ × 1e-18 = 1e-18 ZJ
1 kilojoule = 1e-18 zettajoules.
Real-world example
100 kJ × 1e-18 = 1e-16 ZJ
100 kilojoules = 1e-16 zettajoules.
Conversion table
| Kilojoule (kJ) | Zettajoule (ZJ) |
|---|---|
| 1 kJ | 1e-18 ZJ |
| 10 kJ | 1e-17 ZJ |
| 100 kJ | 1e-16 ZJ |
| 500 kJ | 5e-16 ZJ |
| 1,000 kJ | 1e-15 ZJ |
| 2,000 kJ | 2e-15 ZJ |
Reverse conversion: Zettajoule to Kilojoule
1e-18 ZJ × 1e+18 = 1 kJ
1e-18 zettajoules = 1 kilojoules.
kilojoules = zettajoules × 1e+18
For a page dedicated to this direction, see Zettajoule to Kilojoule.
Understanding the Kilojoule (kJ)
Kilojoule is 1000 joule units.
Understanding the Zettajoule (ZJ)
Zettajoule is 1e+21 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many zettajoules are in 1 kilojoule?
1 kilojoule equals 1e-18 zettajoules, using the exact defined conversion factor rather than an estimate.
How do I convert kilojoule to zettajoule?
Multiply the kilojoule value by 1e-18. The converter above does this instantly to whatever precision you set.
How do I convert zettajoule back to kilojoule?
Use the reverse factor: 1 zettajoule equals 1e+18 kilojoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a kilojoule?
Kilojoule (kJ) is a unit of energy.
What is a zettajoule?
Zettajoule (ZJ) is a unit of energy.
Is the kilojoule to zettajoule conversion exact?
Yes. Both kilojoule and zettajoule are defined by fixed standards rather than physical artifacts, so the factor of 1e-18 used above is exact to as many digits as you choose to display.