Convert Rem to Millirem (rem to mrem)
1 rem = 1000 millirem (mrem). 1 mrem = 0.001 rem. Example: 15 rem = 15 × 1000 = 15000 mrem.
Also searched as rem to mrem, rem in mrem, rem into millirem, rem in millirem, rem to millirem, rem to millirem converter and how many millirem in a rem.
1 rem = 1000 mrem
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk rem to millirem converter to paste a column from Excel.
How to Convert Rem to Millirem
- 1 rem = 1000 mrem
- 1 mrem = 0.001 rem
- Example: convert 15 rem to mrem: 15 rem = 15 × 1000 mrem = 15000 mrem
Formula
mrem = rem × 1000
Derivation from SI units:
- 1 rem = 0.01 Sv.
- 1 mrem = 10⁻⁵ Sv = 10 µSv.
- 1 rem = 0.01 Sv ÷ 0.00001 Sv per mrem = 1000 mrem
Both units are defined exactly, so the factor is exact. Rem definition: rem; Millirem definition: millirem.
Worked examples
- A reading of 5 rem converts to 5000 mrem.
5 rem × 1000 = 5000 mrem - A value of 50 rem is 50000 mrem.
50 rem × 1000 = 50000 mrem
Rem to Millirem conversion table
| Rem | Millirem (mrem) |
|---|---|
| 0.1 rem | 100 mrem |
| 0.5 rem | 500 mrem |
| 1 rem | 1000 mrem |
| 5 rem | 5000 mrem |
| 10 rem | 10000 mrem |
| 25 rem | 25000 mrem |
| 50 rem | 50000 mrem |
| 100 rem | 100000 mrem |
| 400 rem | 400000 mrem |
| 1000 rem | 1000000 mrem |
Where it's used
Rem are used for US NRC dose limits (5 rem/yr occupational), while millirem appear in US public dose limit (100 mrem/yr). Both measure equivalent and effective radiation dose, so the conversion is a fixed factor.
Rem to other equivalent dose units
| Conversion | 1 rem equals |
|---|---|
| rem to millirem | 1000 mrem |
| rem to sievert | 0.01 Sv |
| rem to millisievert | 10 mSv |
| rem to microsievert | 10000 µSv |
| rem to nanosievert | 10000000 nSv |
Frequently asked questions
How many millirem are in 1 rem?
1 rem = 1000 mrem.
How do I convert rem to millirem?
Multiply the value in rem by 1000. For example, 15 rem × 1000 = 15000 mrem.
Is the rem to mrem conversion exact?
Yes. Both units are defined exactly, and 1 rem is exactly 1000 mrem.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "rem".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Rem to Millirem (rem to mrem). Retrieved October 25, 2026, from https://scientificconverters.com/equivalent-dose/rem-to-millirem/
IEEE
Scientific Converters, "Convert Rem to Millirem (rem to mrem)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/equivalent-dose/rem-to-millirem/