Convert Millirem to Microsieverts (mrem to µSv)

Formula

µSv = mrem × 10

Derivation from SI units:

• 1 mrem = 10⁻⁵ Sv = 10 µSv.
• 1 µSv = 10⁻⁶ Sv.
• 1 mrem = 0.00001 Sv ÷ 0.000001 Sv per µSv = 10 µSv

Both units are defined exactly, so the factor is exact. Millirem definition: millirem; Microsievert definition: microsievert.

Worked examples

1. A reading of 20 mrem converts to 200 µSv.
   20 mrem × 10 = 200 µSv
2. A value of 620 mrem is 6200 µSv.
   620 mrem × 10 = 6200 µSv

Where it's used

Millirem are used for US public dose limit (100 mrem/yr), while microsieverts appear in geiger counter and dosimeter readings (µSv/h). Both measure equivalent and effective radiation dose, so the conversion is a fixed factor.

Millirem to other equivalent dose units

Frequently asked questions

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".
• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (becquerel, gray, sievert, lux) and Table 2 (candela).

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.