Radiation Converter

Convert radiation units for dose equivalent (sievert, rem), absorbed dose (gray, rad), radioactivity (becquerel, curie) and exposure (roentgen).

How to use the Radiation Converter

  1. Type the value you want to convert in the first box.
  2. Choose the unit you are converting from and the unit you want to convert to.
  3. Read the result instantly. Use the swap button to reverse the direction, or copy the result with one click.

Popular radiation conversions

ConversionResultFormula
Sieverts to rem1 Sv = 100 remrem = sieverts × 100
Rem to sieverts1 rem = 0.01 Svsieverts = rem ÷ 100
Millisieverts to millirem1 mSv = 100 mremmillirem = millisieverts × 100
Millirem to millisieverts1 mrem = 0.01 mSvmillisieverts = millirem ÷ 100
Grays to rad1 Gy = 100 radrad = grays × 100
Rad to grays1 rad = 0.01 Gygrays = rad ÷ 100
Curies to becquerels1 Ci = 37,000,000,000 Bqbecquerels = curies × 37,000,000,000
Becquerels to curies1 Bq = 2.7027 × 10-11 Cicuries = becquerels ÷ 37,000,000,000

Supported radiation units

UnitSymbolGroup
SievertSvDose equivalent
MillisievertmSvDose equivalent
MicrosievertµSvDose equivalent
RemremDose equivalent
MilliremmremDose equivalent
GrayGyAbsorbed dose
MilligraymGyAbsorbed dose
MicrograyµGyAbsorbed dose
CentigraycGyAbsorbed dose
RadradAbsorbed dose
MilliradmradAbsorbed dose
BecquerelBqRadioactivity
KilobecquerelkBqRadioactivity
MegabecquerelMBqRadioactivity
GigabecquerelGBqRadioactivity
CurieCiRadioactivity
MillicuriemCiRadioactivity
MicrocurieµCiRadioactivity
RutherfordRdRadioactivity
Coulomb per kilogramC/kgExposure
RoentgenRExposure
MilliroentgenmRExposure

Four kinds of radiation units

Radiation is measured in four different ways, and units from one group cannot be converted into another without extra information.

  • Radioactivity (becquerel, curie): how many atoms decay per second in a source. 1 Ci = 37 GBq.
  • Absorbed dose (gray, rad): energy deposited per kilogram of material. 1 Gy = 100 rad.
  • Dose equivalent (sievert, rem): absorbed dose weighted for biological effect. 1 Sv = 100 rem.
  • Exposure (roentgen, C/kg): ionization produced in air by X-rays or gamma rays.

For X-rays and gamma rays, 1 Gy of absorbed dose corresponds to 1 Sv. Typical natural background radiation is about 2 to 3 mSv per year, and a chest X-ray is about 0.1 mSv.

This converter is for reference and education. Radiation safety decisions must be made by qualified professionals.

Frequently asked questions

How many rem are in a sievert?

One sievert equals 100 rem, so 1 mSv equals 100 mrem.

How do I convert gray to rad?

Multiply gray by 100. One gray equals 100 rad.

How many becquerels are in a curie?

One curie is 3.7 × 10¹⁰ becquerels (37 GBq).

Can I convert becquerels to sieverts?

Not directly. Becquerels measure a source's activity and sieverts measure dose to a person; the link depends on the isotope, distance, time and type of exposure.

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