Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Rem to Millisieverts
Convert rem to mSv instantly, then review the formula, assumptions, and rounding guidance.
Radiation unitsInstant result
Decimals
Formula result = input × 0.01 ÷ 0.001. 1 rem = 10 mSv
Common examples
One value, several units
Sieverts0.01 Sv
Millisieverts10 mSv
Microsieverts10,000 µSv
Conversion table
| rem | mSv |
|---|---|
| 1 rem | 10 mSv |
| 2 rem | 20 mSv |
| 5 rem | 50 mSv |
| 10 rem | 100 mSv |
| 25 rem | 250 mSv |
| 50 rem | 500 mSv |
| 100 rem | 1,000 mSv |
Conversion chart
1 rem10 mSv
5 rem50 mSv
10 rem100 mSv
25 rem250 mSv
50 rem500 mSv
Worked example
1 sievert equals 100 rem.
Unit definition
Rem (rem) One rem equals 0.01 sievert.
Unit history
Rem 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 rem 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
Rem to Millisieverts converts a value measured in Rem (rem) 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 × 0.01 ÷ 0.001
Assumptions
- Rem and Millisieverts represent the same equivalent dose quantity.
- The input is expressed in rem; the output is expressed in mSv.
- Equivalent dose already includes the applicable radiation weighting factor.
Worked example
1 rem = 10 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 rem measurement in a document that expects mSv.
- Compare a rem value with a value reported in millisieverts.
- Check the rem-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 Rem to Millisieverts?
result = input × 0.01 ÷ 0.001 Using the displayed relationship, 1 rem equals 10 mSv.
How many Millisieverts are in one Rem?
One Rem is 10 Millisieverts. The displayed digits may be rounded.
Can I reverse the rem to mSv conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts mSv back to rem.
Is the Rem 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.