Radiation Dose Converter

Radiation dose measures the biological harm that absorbed radiation does to living tissue. The SI unit is the sievert (Sv). It already accounts for how damaging each type of radiation is, which is what makes it the right unit for safety limits and risk, rather than a raw energy figure.

Metric prefixes:

• 1 Sv = 1,000 mSv (millisieverts)
• 1 Sv = 1,000,000 µSv (microsieverts)

Legacy unit (rem):

• 1 rem = 0.01 Sv (10 mSv)
• 1 Sv = 100 rem

Doses in context:

• A chest X-ray: about 0.02 mSv
• A transatlantic flight: about 0.04 mSv
• Average natural background: about 2.4 mSv per year
• A CT scan: 2–10 mSv

Reference limits, which is what most people are really trying to place a number against:

The last two carry a condition that the first three do not, and it is the single most important thing on this page: they describe a dose received in a short time. The same total spread across a career is a completely different situation. A converter sees only the number, never the clock, so treat any comparison it makes with an acute threshold as a rough placement rather than a verdict.

The rem is the old US unit and still shows up in American regulations and dosimeter readouts, so converting rem to sieverts is the usual reason people land here. The shorthand is easy: 1 mSv equals 100 mrem.

Keep three radiation units straight, because they get mixed up constantly. The becquerel counts how many atoms decay (activity). The gray measures how much energy the radiation dumps into matter. The sievert weights that energy by how harmful it is to tissue. For any everyday question about whether a dose is safe, the sievert is the one that answers it. A scary-sounding becquerel figure says nothing on its own.