Femtosievert is 1e-15 sievert units.
Femtosieverts to Microsieverts Converter — fSv to uSv
Convert Femtosievert (fSv) to Microsievert (uSv) using the exact conversion factor (1 femtosievert = 1e-9 microsievert). See the formula, worked examples, and conversion table.
Femtosieverts to Microsieverts 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.
Microsievert is 0.000001 sievert units.
Result = input x 1e-15 / 1e-6.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Femtosieverts to Microsieverts
Femtosievert and Microsievert 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 microsievert is 0.000001 sievert units.
Formula
microsieverts = femtosieverts × 1e-9
This factor comes from each unit's defined relationship to the category's base unit: 1 femtosievert equals 1e-15 base units, and 1 microsievert equals 0.000001 base units, so dividing one by the other gives the direct femtosievert-to-microsievert factor of 1e-9.
Simple example
1 fSv × 1e-9 = 1e-9 uSv
1 femtosievert = 1e-9 microsieverts.
Real-world example
10 fSv × 1e-9 = 1e-8 uSv
10 femtosieverts = 1e-8 microsieverts.
Conversion table
| Femtosievert (fSv) | Microsievert (uSv) |
|---|---|
| 0.001 fSv | 1e-12 uSv |
| 0.01 fSv | 1e-11 uSv |
| 0.1 fSv | 1e-10 uSv |
| 1 fSv | 1e-9 uSv |
| 10 fSv | 1e-8 uSv |
| 100 fSv | 1e-7 uSv |
Reverse conversion: Microsievert to Femtosievert
1e-9 uSv × 1000000000 = 1 fSv
1e-9 microsieverts = 1 femtosievert.
femtosieverts = microsieverts × 1000000000
For a page dedicated to this direction, see Microsievert to Femtosievert.
Understanding the Femtosievert (fSv)
Femtosievert is 1e-15 sievert units.
Understanding the Microsievert (uSv)
Microsievert is 0.000001 sievert units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many microsieverts are in 1 femtosievert?
1 femtosievert equals 1e-9 microsieverts, using the exact defined conversion factor rather than an estimate.
How do I convert femtosievert to microsievert?
Multiply the femtosievert value by 1e-9. The converter above does this instantly to whatever precision you set.
How do I convert microsievert back to femtosievert?
Use the reverse factor: 1 microsievert equals 1,000,000,000 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 microsievert?
Microsievert (uSv) is a unit of radiation.
Is the femtosievert to microsievert conversion exact?
Yes. Both femtosievert and microsievert are defined by fixed standards rather than physical artifacts, so the factor of 1e-9 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.