Sievert is equivalent dose.
Sieverts to Femtosieverts Converter — Sv to fSv
Convert Sievert (Sv) to Femtosievert (fSv) using the exact conversion factor (1 sievert = 1e+15 femtosievert). See the formula, worked examples, conversion table, history, and common uses.
Sieverts 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 1 / 1e-15.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Sieverts to Femtosieverts
Sievert 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. Sievert is most often used for radiation safety dose limits for workers and the public.
Formula
femtosieverts = sieverts × 1e+15
This factor comes from each unit's defined relationship to the category's base unit: 1 sievert equals 1 base unit, and 1 femtosievert equals 1e-15 base units, so dividing one by the other gives the direct sievert-to-femtosievert factor of 1e+15.
Simple example
1 Sv × 1e+15 = 1e+15 fSv
1 sievert = 1e+15 femtosieverts.
Real-world example
10 Sv × 1e+15 = 1e+16 fSv
10 sieverts = 1e+16 femtosieverts.
Conversion table
| Sievert (Sv) | Femtosievert (fSv) |
|---|---|
| 0.001 Sv | 1e+12 fSv |
| 0.01 Sv | 1e+13 fSv |
| 0.1 Sv | 1e+14 fSv |
| 1 Sv | 1e+15 fSv |
| 10 Sv | 1e+16 fSv |
| 100 Sv | 1e+17 fSv |
Reverse conversion: Femtosievert to Sievert
1e+15 fSv × 1e-15 = 1 Sv
1e+15 femtosieverts = 1 sievert.
sieverts = femtosieverts × 1e-15
For a page dedicated to this direction, see Femtosievert to Sievert.
Understanding the Sievert
Sievert (Sv) measures equivalent radiation dose. The SI derived unit of equivalent radiation dose, weighting the physically absorbed dose (in gray) for how biologically damaging the specific type of radiation is. It is classified as a SI derived unit.
Where it's used: Universal — SI derived unit used worldwide in radiation protection
Sievert vs. gray. The gray measures physically absorbed radiation energy; the sievert adjusts that figure for biological harm, since equal absorbed doses of different radiation types (e.g. alpha particles vs. X-rays) can cause very different amounts of damage.
Uses of the Sievert today
- Radiation safety dose limits for workers and the public
- Medical imaging (CT scan, X-ray) dose reporting
- Background and environmental radiation exposure reporting
History of the Sievert
The sievert is named after Rolf Sievert (1896–1966), a Swedish medical physicist whose research on radiation measurement and safety standards was foundational to modern radiation protection practice; the unit was adopted by the CGPM in 1977.
Historical origin. Sievert was not the invention of a single named person; it developed through the process described above.
Understanding the Femtosievert (fSv)
Femtosievert is 1e-15 sievert units.
Sievert — sources
- BIPM SI Brochure, 9th edition — Official definition of the sievert as an SI derived unit.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtosieverts are in 1 sievert?
1 sievert equals 1e+15 femtosieverts, using the exact defined conversion factor rather than an estimate.
How do I convert sievert to femtosievert?
Multiply the sievert value by 1e+15. The converter above does this instantly to whatever precision you set.
How do I convert femtosievert back to sievert?
Use the reverse factor: 1 femtosievert equals 1e-15 sieverts. You can also use the swap control in the converter above to flip the direction instantly.
What is a sievert?
Sievert (Sv) measures equivalent radiation dose. The SI derived unit of equivalent radiation dose, weighting the physically absorbed dose (in gray) for how biologically damaging the specific type of radiation is. It is classified as a SI derived unit.
What is a femtosievert?
Femtosievert (fSv) is a unit of radiation.
Is the sievert to femtosievert conversion exact?
Yes. Both sievert and femtosievert 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 is the difference between sievert vs. gray?
The gray measures physically absorbed radiation energy; the sievert adjusts that figure for biological harm, since equal absorbed doses of different radiation types (e.g. alpha particles vs. X-rays) can cause very different amounts of damage.
Where is the sievert still used today?
Universal — SI derived unit used worldwide in radiation protection