Attosievert is 1e-18 sievert units.
Attosieverts to Millisieverts Converter — aSv to mSv
Convert Attosievert (aSv) to Millisievert (mSv) using the exact conversion factor (1 attosievert = 1e-15 millisievert). See the formula, worked examples, and conversion table.
Attosieverts to Millisieverts 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.
Millisievert is 0.001 sievert units.
Result = input x 1e-18 / 0.001.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Attosieverts to Millisieverts
Attosievert and Millisievert 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: Attosievert is 1e-18 sievert units, and millisievert is 0.001 sievert units.
Formula
millisieverts = attosieverts × 1e-15
This factor comes from each unit's defined relationship to the category's base unit: 1 attosievert equals 1e-18 base units, and 1 millisievert equals 0.001 base units, so dividing one by the other gives the direct attosievert-to-millisievert factor of 1e-15.
Simple example
1 aSv × 1e-15 = 1e-15 mSv
1 attosievert = 1e-15 millisieverts.
Real-world example
10 aSv × 1e-15 = 1e-14 mSv
10 attosieverts = 1e-14 millisieverts.
Conversion table
| Attosievert (aSv) | Millisievert (mSv) |
|---|---|
| 0.001 aSv | 1e-18 mSv |
| 0.01 aSv | 1e-17 mSv |
| 0.1 aSv | 1e-16 mSv |
| 1 aSv | 1e-15 mSv |
| 10 aSv | 1e-14 mSv |
| 100 aSv | 1e-13 mSv |
Reverse conversion: Millisievert to Attosievert
1e-15 mSv × 1e+15 = 1 aSv
1e-15 millisieverts = 1 attosievert.
attosieverts = millisieverts × 1e+15
For a page dedicated to this direction, see Millisievert to Attosievert.
Understanding the Attosievert (aSv)
Attosievert is 1e-18 sievert units.
Understanding the Millisievert (mSv)
Millisievert is 0.001 sievert units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many millisieverts are in 1 attosievert?
1 attosievert equals 1e-15 millisieverts, using the exact defined conversion factor rather than an estimate.
How do I convert attosievert to millisievert?
Multiply the attosievert value by 1e-15. The converter above does this instantly to whatever precision you set.
How do I convert millisievert back to attosievert?
Use the reverse factor: 1 millisievert equals 1e+15 attosieverts. You can also use the swap control in the converter above to flip the direction instantly.
What is a attosievert?
Attosievert (aSv) is a unit of radiation.
What is a millisievert?
Millisievert (mSv) is a unit of radiation.
Is the attosievert to millisievert conversion exact?
Yes. Both attosievert and millisievert are defined by fixed standards rather than physical artifacts, so the factor of 1e-15 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.