Millisievert is 0.001 sievert units.
Millisieverts to Nanosieverts Converter — mSv to nSv
Convert Millisievert (mSv) to Nanosievert (nSv) using the exact conversion factor (1 millisievert = 1,000,000 nanosievert). See the formula, worked examples, and conversion table.
Millisieverts to Nanosieverts 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.
Nanosievert is 1e-9 sievert units.
Result = input x 0.001 / 1e-9.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Millisieverts to Nanosieverts
Millisievert and Nanosievert 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: Millisievert is 0.001 sievert units, and nanosievert is 1e-9 sievert units.
Formula
nanosieverts = millisieverts × 1000000
This factor comes from each unit's defined relationship to the category's base unit: 1 millisievert equals 0.001 base units, and 1 nanosievert equals 1e-9 base units, so dividing one by the other gives the direct millisievert-to-nanosievert factor of 1000000.
Simple example
1 mSv × 1000000 = 1,000,000 nSv
1 millisievert = 1,000,000 nanosieverts.
Real-world example
10 mSv × 1000000 = 10,000,000 nSv
10 millisieverts = 10,000,000 nanosieverts.
Conversion table
| Millisievert (mSv) | Nanosievert (nSv) |
|---|---|
| 0.001 mSv | 1,000 nSv |
| 0.01 mSv | 10,000 nSv |
| 0.1 mSv | 100,000 nSv |
| 1 mSv | 1,000,000 nSv |
| 10 mSv | 10,000,000 nSv |
| 100 mSv | 100,000,000 nSv |
Reverse conversion: Nanosievert to Millisievert
1 nSv × 0.000001 = 0.000001 mSv
1 nanosievert = 0.000001 millisieverts.
millisieverts = nanosieverts × 0.000001
For a page dedicated to this direction, see Nanosievert to Millisievert.
Understanding the Millisievert (mSv)
Millisievert is 0.001 sievert units.
Understanding the Nanosievert (nSv)
Nanosievert is 1e-9 sievert units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many nanosieverts are in 1 millisievert?
1 millisievert equals 1,000,000 nanosieverts, using the exact defined conversion factor rather than an estimate.
How do I convert millisievert to nanosievert?
Multiply the millisievert value by 1000000. The converter above does this instantly to whatever precision you set.
How do I convert nanosievert back to millisievert?
Use the reverse factor: 1 nanosievert equals 0.000001 millisieverts. You can also use the swap control in the converter above to flip the direction instantly.
What is a millisievert?
Millisievert (mSv) is a unit of radiation.
What is a nanosievert?
Nanosievert (nSv) is a unit of radiation.
Is the millisievert to nanosievert conversion exact?
Yes. Both millisievert and nanosievert 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.