Milligray is 0.001 gray units.
Milligrays to Exagrays Converter — mGy to EGy
Convert Milligray (mGy) to Exagray (EGy) using the exact conversion factor (1 milligray = 1e-21 exagray). See the formula, worked examples, and conversion table.
Milligrays to Exagrays 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.
Exagray is 1000000000000000000 gray units.
Result = input x 0.001 / 1e+18.
Absorbed Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Milligrays to Exagrays
Milligray and Exagray 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: Milligray is 0.001 gray units, and exagray is 1000000000000000000 gray units.
Formula
exagrays = milligrays × 1e-21
This factor comes from each unit's defined relationship to the category's base unit: 1 milligray equals 0.001 base units, and 1 exagray equals 1e+18 base units, so dividing one by the other gives the direct milligray-to-exagray factor of 1e-21.
Simple example
1 mGy × 1e-21 = 1e-21 EGy
1 milligray = 1e-21 exagrays.
Real-world example
10 mGy × 1e-21 = 1e-20 EGy
10 milligrays = 1e-20 exagrays.
Conversion table
| Milligray (mGy) | Exagray (EGy) |
|---|---|
| 0.001 mGy | 1e-24 EGy |
| 0.01 mGy | 1e-23 EGy |
| 0.1 mGy | 1e-22 EGy |
| 1 mGy | 1e-21 EGy |
| 10 mGy | 1e-20 EGy |
| 100 mGy | 1e-19 EGy |
Reverse conversion: Exagray to Milligray
1e-21 EGy × 1e+21 = 1 mGy
1e-21 exagrays = 1 milligrays.
milligrays = exagrays × 1e+21
For a page dedicated to this direction, see Exagray to Milligray.
Understanding the Milligray (mGy)
Milligray is 0.001 gray units.
Understanding the Exagray (EGy)
Exagray is 1000000000000000000 gray units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many exagrays are in 1 milligray?
1 milligray equals 1e-21 exagrays, using the exact defined conversion factor rather than an estimate.
How do I convert milligray to exagray?
Multiply the milligray value by 1e-21. The converter above does this instantly to whatever precision you set.
How do I convert exagray back to milligray?
Use the reverse factor: 1 exagray equals 1e+21 milligrays. You can also use the swap control in the converter above to flip the direction instantly.
What is a milligray?
Milligray (mGy) is a unit of radiation.
What is a exagray?
Exagray (EGy) is a unit of radiation.
Is the milligray to exagray conversion exact?
Yes. Both milligray and exagray 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.
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.