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