Kilogray is 1000 gray units.
Kilograys to Femtograys Converter — kGy to fGy
Convert Kilogray (kGy) to Femtogray (fGy) using the exact conversion factor (1 kilogray = 1e+18 femtogray). See the formula, worked examples, and conversion table.
Kilograys to Femtograys 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.
Femtogray is 1e-15 gray units.
Result = input x 1000 / 1e-15.
Absorbed Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Kilograys to Femtograys
Kilogray and Femtogray 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 femtogray is 1e-15 gray units.
Formula
femtograys = 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 femtogray equals 1e-15 base units, so dividing one by the other gives the direct kilogray-to-femtogray factor of 1e+18.
Simple example
1 kGy × 1e+18 = 1e+18 fGy
1 kilogray = 1e+18 femtograys.
Real-world example
10 kGy × 1e+18 = 1e+19 fGy
10 kilograys = 1e+19 femtograys.
Conversion table
| Kilogray (kGy) | Femtogray (fGy) |
|---|---|
| 0.001 kGy | 1e+15 fGy |
| 0.01 kGy | 1e+16 fGy |
| 0.1 kGy | 1e+17 fGy |
| 1 kGy | 1e+18 fGy |
| 10 kGy | 1e+19 fGy |
| 100 kGy | 1e+20 fGy |
Reverse conversion: Femtogray to Kilogray
1e+18 fGy × 1e-18 = 1 kGy
1e+18 femtograys = 1 kilograys.
kilograys = femtograys × 1e-18
For a page dedicated to this direction, see Femtogray to Kilogray.
Understanding the Kilogray (kGy)
Kilogray is 1000 gray units.
Understanding the Femtogray (fGy)
Femtogray is 1e-15 gray units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtograys are in 1 kilogray?
1 kilogray equals 1e+18 femtograys, using the exact defined conversion factor rather than an estimate.
How do I convert kilogray to femtogray?
Multiply the kilogray value by 1e+18. The converter above does this instantly to whatever precision you set.
How do I convert femtogray back to kilogray?
Use the reverse factor: 1 femtogray 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 femtogray?
Femtogray (fGy) is a unit of radiation.
Is the kilogray to femtogray conversion exact?
Yes. Both kilogray and femtogray 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.