Kilogray is 1000 gray units.
Kilograys to Zettagrays Converter — kGy to ZGy
Convert Kilogray (kGy) to Zettagray (ZGy) using the exact conversion factor (1 kilogray = 1e-18 zettagray). See the formula, worked examples, and conversion table.
Kilograys to Zettagrays converter
Converter
Radiation Converter
Convert radioactivity, absorbed dose, and equivalent dose units by compatible radiation family.
Context values
Some unit families need one extra value for a physically accurate result.
Zettagray is 1e+21 gray units.
Result = input x 1000 / 1e+21.
Absorbed Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Kilograys to Zettagrays
Kilogray and Zettagray both belong to the radiation-measurement family, though radiation quantities fall into genuinely distinct categories: absorbed dose (gray, rad) measures energy deposited in matter, equivalent dose (sievert, rem) weights that for biological harm, and activity (becquerel, curie) measures how often a radioactive source decays — this page only converts between units of the same kind. Specifically: Kilogray is 1000 gray units, and zettagray is 1e+21 gray units.
Formula
zettagrays = kilograys × 1e-18
This factor comes from each unit's defined relationship to the category's base unit: 1 kilogray equals 1000 base units, and 1 zettagray equals 1e+21 base units, so dividing one by the other gives the direct kilogray-to-zettagray factor of 1e-18.
Simple example
1 kGy × 1e-18 = 1e-18 ZGy
1 kilogray = 1e-18 zettagrays.
Real-world example
10 kGy × 1e-18 = 1e-17 ZGy
10 kilograys = 1e-17 zettagrays.
Conversion table
| Kilogray (kGy) | Zettagray (ZGy) |
|---|---|
| 0.001 kGy | 1e-21 ZGy |
| 0.01 kGy | 1e-20 ZGy |
| 0.1 kGy | 1e-19 ZGy |
| 1 kGy | 1e-18 ZGy |
| 10 kGy | 1e-17 ZGy |
| 100 kGy | 1e-16 ZGy |
Reverse conversion: Zettagray to Kilogray
1e-18 ZGy × 1e+18 = 1 kGy
1e-18 zettagrays = 1 kilograys.
kilograys = zettagrays × 1e+18
For a page dedicated to this direction, see Zettagray to Kilogray.
Understanding the Kilogray (kGy)
Kilogray is 1000 gray units.
Understanding the Zettagray (ZGy)
Zettagray is 1e+21 gray units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many zettagrays are in 1 kilogray?
1 kilogray equals 1e-18 zettagrays, using the exact defined conversion factor rather than an estimate.
How do I convert kilogray to zettagray?
Multiply the kilogray value by 1e-18. The converter above does this instantly to whatever precision you set.
How do I convert zettagray back to kilogray?
Use the reverse factor: 1 zettagray equals 1e+18 kilograys. You can also use the swap control in the converter above to flip the direction instantly.
What is a kilogray?
Kilogray (kGy) is a unit of radiation.
What is a zettagray?
Zettagray (ZGy) is a unit of radiation.
Is the kilogray to zettagray conversion exact?
Yes. Both kilogray and zettagray 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.
What's the difference between absorbed dose, equivalent dose, and activity?
Absorbed dose (gray, rad) measures the energy radiation deposits in matter. Equivalent dose (sievert, rem) adjusts that figure for how harmful different types of radiation are to biological tissue. Activity (becquerel, curie) measures how often a radioactive source decays, independent of how much dose a person actually receives from it.