Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Sieverts to Millisieverts
Convert Sv to mSv instantly, then review the formula, assumptions, and rounding guidance.
Radiation unitsInstant result
Decimals
Formula result = input × 1 ÷ 0.001. 1 Sv = 1,000 mSv
Common examples
One value, several units
Millisieverts1,000 mSv
Microsieverts1,000,000 µSv
Rem100 rem
Conversion table
| Sv | mSv |
|---|---|
| 1 Sv | 1,000 mSv |
| 2 Sv | 2,000 mSv |
| 5 Sv | 5,000 mSv |
| 10 Sv | 10,000 mSv |
| 25 Sv | 25,000 mSv |
| 50 Sv | 50,000 mSv |
| 100 Sv | 100,000 mSv |
Conversion chart
1 Sv1,000 mSv
5 Sv5,000 mSv
10 Sv10,000 mSv
25 Sv25,000 mSv
50 Sv50,000 mSv
Worked example
1 sievert equals 100 rem.
Unit definition
Sieverts (Sv) One sieverts equals 1 sievert.
Unit history
Sieverts is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert Sv to sievert.
3. Convert the base value to mSv and apply your display precision.
Important
Equivalent dose already includes the applicable radiation weighting factor.
Understand the result before using it
Sieverts to Millisieverts converts a value measured in Sieverts (Sv) into the equivalent value in Millisieverts (mSv). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 1 ÷ 0.001
Assumptions
- Sieverts and Millisieverts represent the same equivalent dose quantity.
- The input is expressed in Sv; the output is expressed in mSv.
- Equivalent dose already includes the applicable radiation weighting factor.
Worked example
1 Sv = 1,000 mSv. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a Sv measurement in a document that expects mSv.
- Compare a sieverts value with a value reported in millisieverts.
- Check the Sv-to-mSv arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Absorbed dose, equivalent dose, and activity describe different radiation quantities and are not interchangeable.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Sieverts to Millisieverts?
result = input × 1 ÷ 0.001 Using the displayed relationship, 1 Sv equals 1,000 mSv.
How many Millisieverts are in one Sieverts?
One Sieverts is 1,000 Millisieverts. The displayed digits may be rounded.
Can I reverse the Sv to mSv conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts mSv back to Sv.
Is the Sieverts to Millisieverts result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.