Femtosievert is 1e-15 sievert units.
Femtosieverts to Zeptosieverts Converter — fSv to zSv
Convert Femtosievert (fSv) to Zeptosievert (zSv) using the exact conversion factor (1 femtosievert = 1,000,000 zeptosievert). See the formula, worked examples, and conversion table.
Femtosieverts to Zeptosieverts 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.
Zeptosievert is 1e-21 sievert units.
Result = input x 1e-15 / 1e-21.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Femtosieverts to Zeptosieverts
Femtosievert and Zeptosievert 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 zeptosievert is 1e-21 sievert units.
Formula
zeptosieverts = femtosieverts × 1000000
This factor comes from each unit's defined relationship to the category's base unit: 1 femtosievert equals 1e-15 base units, and 1 zeptosievert equals 1e-21 base units, so dividing one by the other gives the direct femtosievert-to-zeptosievert factor of 1000000.
Simple example
1 fSv × 1000000 = 1,000,000 zSv
1 femtosievert = 1,000,000 zeptosieverts.
Real-world example
10 fSv × 1000000 = 10,000,000 zSv
10 femtosieverts = 10,000,000 zeptosieverts.
Conversion table
| Femtosievert (fSv) | Zeptosievert (zSv) |
|---|---|
| 0.001 fSv | 1,000 zSv |
| 0.01 fSv | 10,000 zSv |
| 0.1 fSv | 100,000 zSv |
| 1 fSv | 1,000,000 zSv |
| 10 fSv | 10,000,000 zSv |
| 100 fSv | 100,000,000 zSv |
Reverse conversion: Zeptosievert to Femtosievert
1 zSv × 1e-6 = 1e-6 fSv
1 zeptosievert = 1e-6 femtosieverts.
femtosieverts = zeptosieverts × 1e-6
For a page dedicated to this direction, see Zeptosievert to Femtosievert.
Understanding the Femtosievert (fSv)
Femtosievert is 1e-15 sievert units.
Understanding the Zeptosievert (zSv)
Zeptosievert is 1e-21 sievert units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many zeptosieverts are in 1 femtosievert?
1 femtosievert equals 1,000,000 zeptosieverts, using the exact defined conversion factor rather than an estimate.
How do I convert femtosievert to zeptosievert?
Multiply the femtosievert value by 1000000. The converter above does this instantly to whatever precision you set.
How do I convert zeptosievert back to femtosievert?
Use the reverse factor: 1 zeptosievert equals 1e-6 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 zeptosievert?
Zeptosievert (zSv) is a unit of radiation.
Is the femtosievert to zeptosievert conversion exact?
Yes. Both femtosievert and zeptosievert are defined by fixed standards rather than physical artifacts, so the factor of 1000000 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.