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Gray to Sievert Converter

Multiply an absorbed dose in grays (Gy) by the radiation weighting factor to estimate the equivalent dose in sieverts (Sv). Pick a radiation type and see mSv and μSv at once.

Input

Enter an absorbed dose in grays (Gy) and pick the type of radiation to estimate the equivalent dose in sieverts (Sv). The formula is Sv = Gy × radiation weighting factor WR.

Gy
Type of radiation

Photons. X-rays are treated the same way.

Result

Equivalent dose (estimate)

0.1Sv

Weighting factor WR

1

Type of radiation

Gamma rays (γ)

Absorbed dose

0.1 Gy

Equivalent dose by unit

UnitEquivalent dose
Sievert (Sv)0.1 Sv
Millisievert (mSv)100 mSv
Microsievert (μSv)100,000 μSv

Equivalent dose H = absorbed dose D × radiation weighting factor WR. Gamma rays, X-rays and beta rays have WR = 1, so their Gy and Sv values are numerically identical. This result is a rough estimate for educational reference only; for radiation protection or exposure management, always consult official sources.

How it works

  • This calculation uses the relation equivalent dose H = absorbed dose D × radiation weighting factor WR. Multiplying the absorbed dose in grays (Gy) by the weighting factor defined for each radiation type gives the equivalent dose in sieverts (Sv), which accounts for the effect on the human body.
  • The gray (Gy) is a physical quantity expressing the energy absorbed per kilogram of matter (J/kg), while the sievert (Sv) factors in the biological impact on the body. Because the same Gy can have different effects depending on the radiation type, the weighting factor corrects for this.
  • The representative radiation weighting factors WR used here are: gamma rays, X-rays and beta rays = 1, protons = 2, alpha rays = 20. Since gamma, X-ray and beta have WR = 1, their Gy and Sv values are identical.
  • The weighting factor for neutrons depends strongly on energy and varies roughly between 2.5 and 20. This tool uses a mid-range representative value of 10 as an estimate; accurate evaluation requires the neutron energy spectrum.
  • The equivalent dose handled here is an indicator of the dose received by a particular organ or tissue. Effective dose (also in Sv), which evaluates whole-body stochastic effects, additionally requires tissue weighting factors and therefore has a different meaning from the value shown here.
  • The results of this tool are estimates for educational reference. For actual exposure assessment, radiation protection, or medical exposure decisions, refer to the latest information from nuclear regulatory authorities and other official bodies, and to expert judgement.