1 Sv is equivalent to how many rem?

• A. 100 rem
• B. 1 rem
• C. 10 rem
• D. 1000 rem

Answer: (A)

Dose equivalents use two units that express the same idea: the biological effect of radiation. The rem is the older unit, while the sievert is the modern SI unit. They are tied by a fixed factor: 1 sievert equals 100 rem. That means the rem is equal to 0.01 sievert, so 1 sievert corresponds to 100 rem. For example, 0.5 sievert is 50 rem, and 0.01 sievert is 1 rem. In many diagnostic contexts the radiation weighting factor is 1, so the numerical values for dose in sieverts and grays map straightforwardly to biological effect, but the 100-to-1 relationship between sieverts and rem remains the standard conversion.