Radiation Dose Equivalent Calculator

How it is calculated

The absorbed dose D is entered in grays (Gy) and the radiation type is picked from a list. The tool multiplies by a fixed weighting factor: H = D × wR, giving the dose equivalent H in sieverts (Sv). The factors built in are 1 for X-rays, gamma rays and beta particles, 2 for protons, 10 for neutrons and 20 for alpha particles. The result is also shown in millisieverts (mSv = Sv × 1000) along with the factor used. Negative doses give no result, and the figures are rounded to four decimals, so very small doses show as 0.0000 Sv and are better read in the mSv line. The neutron factor is a single flat value here, although in practice it depends on neutron energy. Dose equivalent describes radiation type only, not which organs were exposed.

Common mistakes

• Entering a dose in sieverts or millisieverts. The input is the absorbed dose in grays; typing a value already in Sv applies the weighting twice for heavy particles.
• Entering milligray as gray. 5 mGy is 0.005 Gy, not 5; a factor-of-1000 slip changes the answer from 5 mSv to 5 Sv for gamma rays.
• Assuming an unknown or unselected type is rejected. Anything outside the six listed types is treated as factor 1, so always check the weighting factor shown in the result.
• Reading a 0.0000 Sv result as zero exposure. Small doses are rounded at four decimals in the sievert line, so use the millisievert value instead.
• Treating the result as a whole-body risk figure. It only applies the radiation-type factor; it does not weight different organs or tissues.