Rem to Millisievert Converter (rem ⇄ mSv)
Convert radiation equivalent dose between rem and millisievert (mSv) instantly, with clear formulas, examples, and safety context.
Rem ⇄ Millisievert Calculator
1 rem = 10 mSv
Result: – mSv
1 mSv = 0.1 rem
Result: – rem
Quick rem ⇄ mSv reference
| rem | mSv | Typical context |
|---|---|---|
| 0.01 rem | 0.1 mSv | Approx. one chest X‑ray |
| 0.03 rem | 0.3 mSv | Average monthly background dose |
| 0.1 rem | 1 mSv | Typical annual public dose limit (many countries) |
| 0.5 rem | 5 mSv | Diagnostic CT scan range |
| 5 rem | 50 mSv | Typical annual limit for radiation workers |
Values are approximate and for educational context only. Always follow local regulations and professional guidance.
How the rem to millisievert conversion works
Both rem and sievert (Sv) are units of equivalent dose or effective dose – they describe the biological effect of ionizing radiation on the body, not just the physical energy absorbed.
Rem is an older, non‑SI unit. Sievert is the modern SI unit. The exact relationship is:
Base relationship
1 Sv = 100 rem
1 rem = 0.01 Sv
Using millisieverts
1 Sv = 1000 mSv
1 rem = 0.01 Sv = 0.01 × 1000 mSv = 10 mSv
Formulas
Rem to millisievert
\( \text{mSv} = \text{rem} \times 10 \)
Millisievert to rem
\( \text{rem} = \dfrac{\text{mSv}}{10} \)
Worked examples
Example 1 – Convert 0.25 rem to mSv
You have a dose of 0.25 rem and want millisieverts:
- mSv = 0.25 × 10 = 2.5 mSv
Example 2 – Convert 75 mSv to rem
You have a dose of 75 mSv and want rem:
- rem = 75 ÷ 10 = 7.5 rem
Typical radiation doses (rem and mSv)
The table below gives rough orders of magnitude for common exposures. Actual values vary by equipment, procedure, and environment.
| Situation | Approx. dose |
|---|---|
| Natural background radiation (per year) | 0.2–0.3 rem (2–3 mSv) |
| Chest X‑ray | ~0.01 rem (0.1 mSv) |
| CT scan (abdomen) | ~0.5–1 rem (5–10 mSv) |
| Annual public dose limit (many regulations) | 0.1 rem (1 mSv) |
| Annual occupational limit (radiation worker) | 5 rem (50 mSv) |
These values are approximate and for educational purposes only. Always consult official guidelines and a qualified health physics or medical professional for risk assessment.
rem, sievert, and biological effect
Equivalent dose accounts for the fact that different types of radiation (gamma, X‑ray, neutron, alpha, etc.) cause different levels of biological damage for the same absorbed dose in gray (Gy).
In simplified form:
\( H_T = D_T \times w_R \)
where \(H_T\) is equivalent dose in a tissue T (Sv or rem), \(D_T\) is absorbed dose in gray (Gy), and \(w_R\) is the radiation weighting factor (formerly quality factor).
Rem and sievert both measure this equivalent or effective dose. The difference is purely the numerical scale (factor of 100).
Safety and limitations
- This tool converts units only; it does not assess health risk.
- Risk depends on dose, dose rate, radiation type, exposed tissues, and individual sensitivity.
- For medical or occupational decisions, always follow local regulations and consult radiation protection experts or physicians.
FAQ: rem to millisievert
How do you convert rem to millisievert?
Multiply the value in rem by 10. The exact formula is: mSv = rem × 10. This comes from 1 rem = 0.01 Sv and 1 Sv = 1000 mSv, so 1 rem = 10 mSv.
How do you convert millisievert to rem?
Divide the value in mSv by 10. The formula is: rem = mSv ÷ 10. For example, 20 mSv = 2 rem.
What is the difference between rem and sievert?
Rem is an older, non‑SI unit; sievert (Sv) is the modern SI unit. They measure the same quantity (equivalent or effective dose), but 1 Sv = 100 rem. Most modern standards use Sv and its submultiples (mSv, µSv), while rem appears in older U.S. regulations and documents.
Is 1 rem a high radiation dose?
1 rem (10 mSv) is higher than typical background radiation but well below levels that cause acute radiation sickness. It is, however, a non‑trivial dose in terms of long‑term risk. For comparison, many regulations set public exposure limits around 0.1 rem (1 mSv) per year, and occupational limits around 5 rem (50 mSv) per year.
When should I use rem vs mSv?
Use mSv (or Sv) for compatibility with modern scientific literature and international standards. Use rem only when you are working with legacy documents, older instruments, or regulations that still specify limits in rem. This converter lets you move easily between the two.