Attosievert is 1e-18 sievert units.
Attosieverts to Femtosieverts Converter — aSv to fSv
Convert Attosievert (aSv) to Femtosievert (fSv) using the exact conversion factor (1 attosievert = 0.001 femtosievert). See the formula, worked examples, and conversion table.
Attosieverts to Femtosieverts 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.
Femtosievert is 1e-15 sievert units.
Result = input x 1e-18 / 1e-15.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Attosieverts to Femtosieverts
Attosievert and Femtosievert 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 femtosievert is 1e-15 sievert units.
Formula
femtosieverts = attosieverts × 0.001
This factor comes from each unit's defined relationship to the category's base unit: 1 attosievert equals 1e-18 base units, and 1 femtosievert equals 1e-15 base units, so dividing one by the other gives the direct attosievert-to-femtosievert factor of 0.001.
Simple example
1 aSv × 0.001 = 0.001 fSv
1 attosievert = 0.001 femtosieverts.
Real-world example
10 aSv × 0.001 = 0.01 fSv
10 attosieverts = 0.01 femtosieverts.
Conversion table
| Attosievert (aSv) | Femtosievert (fSv) |
|---|---|
| 0.001 aSv | 0.000001 fSv |
| 0.01 aSv | 0.00001 fSv |
| 0.1 aSv | 0.0001 fSv |
| 1 aSv | 0.001 fSv |
| 10 aSv | 0.01 fSv |
| 100 aSv | 0.1 fSv |
Reverse conversion: Femtosievert to Attosievert
0.001 fSv × 1000 = 1 aSv
0.001 femtosieverts = 1 attosievert.
attosieverts = femtosieverts × 1000
For a page dedicated to this direction, see Femtosievert to Attosievert.
Understanding the Attosievert (aSv)
Attosievert is 1e-18 sievert units.
Understanding the Femtosievert (fSv)
Femtosievert is 1e-15 sievert units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtosieverts are in 1 attosievert?
1 attosievert equals 0.001 femtosieverts, using the exact defined conversion factor rather than an estimate.
How do I convert attosievert to femtosievert?
Multiply the attosievert value by 0.001. The converter above does this instantly to whatever precision you set.
How do I convert femtosievert back to attosievert?
Use the reverse factor: 1 femtosievert equals 1,000 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 femtosievert?
Femtosievert (fSv) is a unit of radiation.
Is the attosievert to femtosievert conversion exact?
Yes. Both attosievert and femtosievert are defined by fixed standards rather than physical artifacts, so the factor of 0.001 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.