Millisievert is 0.001 sievert units.
Millisieverts to Rems Converter — mSv to rem
Convert Millisievert (mSv) to Rem (rem) using the exact conversion factor (1 millisievert = 0.1 rem). See the formula, worked examples, conversion table, and common uses.
Millisieverts to Rems 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.
Rem is 0.01 sievert.
Result = input x 0.001 / 0.01.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Millisieverts to Rems
Millisievert and Rem 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 rem is 0.01 sievert.
Formula
rems = millisieverts × 0.1
This factor comes from each unit's defined relationship to the category's base unit: 1 millisievert equals 0.001 base units, and 1 rem equals 0.01 base units, so dividing one by the other gives the direct millisievert-to-rem factor of 0.1.
Simple example
1 mSv × 0.1 = 0.1 rem
1 millisievert = 0.1 rems.
Real-world example
10 mSv × 0.1 = 1 rem
10 millisieverts = 1 rem.
Conversion table
| Millisievert (mSv) | Rem (rem) |
|---|---|
| 0.001 mSv | 0.0001 rem |
| 0.01 mSv | 0.001 rem |
| 0.1 mSv | 0.01 rem |
| 1 mSv | 0.1 rem |
| 10 mSv | 1 rem |
| 100 mSv | 10 rem |
Reverse conversion: Rem to Millisievert
0.1 rem × 10 = 1 mSv
0.1 rems = 1 millisievert.
millisieverts = rems × 10
For a page dedicated to this direction, see Rem to Millisievert.
Understanding the Millisievert (mSv)
Millisievert is 0.001 sievert units.
Understanding the Rem
Rem (rem) measures equivalent radiation dose. 'Roentgen equivalent man' — the US customary unit of equivalent radiation dose, fixed at exactly 0.01 sievert. It is classified as a non-SI unit, still common in the US.
Where it's used: Still widely used in the United States alongside the SI sievert
Rem vs. sievert. Both measure equivalent radiation dose; the sievert is the modern SI unit while the rem is the older US customary unit, related by 1 sievert = 100 rem exactly.
Uses of the Rem today
- US occupational radiation dose limits and monitoring
- US nuclear regulatory reporting
- US medical radiation dose records
Rem — sources
- US NRC (Nuclear Regulatory Commission) — glossary — Definition and continued regulatory use of the rem in the United States.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many rems are in 1 millisievert?
1 millisievert equals 0.1 rems, using the exact defined conversion factor rather than an estimate.
How do I convert millisievert to rem?
Multiply the millisievert value by 0.1. The converter above does this instantly to whatever precision you set.
How do I convert rem back to millisievert?
Use the reverse factor: 1 rem equals 10 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 rem?
Rem (rem) measures equivalent radiation dose. 'Roentgen equivalent man' — the US customary unit of equivalent radiation dose, fixed at exactly 0.01 sievert. It is classified as a non-SI unit, still common in the US.
Is the millisievert to rem conversion exact?
Yes. 'Roentgen equivalent man' — the US customary unit of equivalent radiation dose, fixed at exactly 0.01 sievert. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between rem vs. sievert?
Both measure equivalent radiation dose; the sievert is the modern SI unit while the rem is the older US customary unit, related by 1 sievert = 100 rem exactly.