Zeptosievert is 1e-21 sievert units.
Zeptosieverts to Femtosieverts Converter — zSv to fSv
Convert Zeptosievert (zSv) to Femtosievert (fSv) using the exact conversion factor (1 zeptosievert = 1e-6 femtosievert). See the formula, worked examples, and conversion table.
Zeptosieverts 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-21 / 1e-15.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Zeptosieverts to Femtosieverts
Zeptosievert 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: Zeptosievert is 1e-21 sievert units, and femtosievert is 1e-15 sievert units.
Formula
femtosieverts = zeptosieverts × 1e-6
This factor comes from each unit's defined relationship to the category's base unit: 1 zeptosievert equals 1e-21 base units, and 1 femtosievert equals 1e-15 base units, so dividing one by the other gives the direct zeptosievert-to-femtosievert factor of 1e-6.
Simple example
1 zSv × 1e-6 = 1e-6 fSv
1 zeptosievert = 1e-6 femtosieverts.
Real-world example
10 zSv × 1e-6 = 0.00001 fSv
10 zeptosieverts = 0.00001 femtosieverts.
Conversion table
| Zeptosievert (zSv) | Femtosievert (fSv) |
|---|---|
| 0.001 zSv | 1e-9 fSv |
| 0.01 zSv | 1e-8 fSv |
| 0.1 zSv | 1e-7 fSv |
| 1 zSv | 1e-6 fSv |
| 10 zSv | 0.00001 fSv |
| 100 zSv | 0.0001 fSv |
Reverse conversion: Femtosievert to Zeptosievert
0.000001 fSv × 1000000 = 1 zSv
0.000001 femtosieverts = 1 zeptosieverts.
zeptosieverts = femtosieverts × 1000000
For a page dedicated to this direction, see Femtosievert to Zeptosievert.
Understanding the Zeptosievert (zSv)
Zeptosievert is 1e-21 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 zeptosievert?
1 zeptosievert equals 1e-6 femtosieverts, using the exact defined conversion factor rather than an estimate.
How do I convert zeptosievert to femtosievert?
Multiply the zeptosievert value by 1e-6. The converter above does this instantly to whatever precision you set.
How do I convert femtosievert back to zeptosievert?
Use the reverse factor: 1 femtosievert equals 1,000,000 zeptosieverts. You can also use the swap control in the converter above to flip the direction instantly.
What is a zeptosievert?
Zeptosievert (zSv) is a unit of radiation.
What is a femtosievert?
Femtosievert (fSv) is a unit of radiation.
Is the zeptosievert to femtosievert conversion exact?
Yes. Both zeptosievert and femtosievert are defined by fixed standards rather than physical artifacts, so the factor of 1e-6 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.