Unit Conversion

Convert numbers between two units quickly and precisely

Radiation

Unit Conversion

Convert radioactivity: becquerel and curie

The activity of a radioactive source – the number of nuclear decays per unit time – is stated in becquerel (Bq), the SI unit, as well as megabecquerel (MBq) and gigabecquerel (GBq). The older unit curie (Ci) is still commonly used, especially in nuclear medicine.

Key conversion factors:

  • 1 becquerel (Bq) = 1 decay per second
  • 1 megabecquerel (MBq) = 1,000,000 becquerel
  • 1 curie (Ci) = 37,000,000,000 becquerel (3.7 * 10^10 Bq)

Applications:

  • Nuclear medicine: activity figures for radioactive tracers in MBq
  • Radiation protection: assessing the activity of radioactive sources and samples

The radioactivity converter converts between becquerel and curie. Note: absorbed dose (gray) and equivalent dose (sievert) are physically different quantities from activity and cannot be converted with a fixed factor – they depend on radiation type, energy, and exposed tissue, and require a separate dose converter.

Frequently asked questions about converting radioactivity

1 curie (Ci) equals 37,000,000,000 becquerel (3.7 * 10^10 Bq). Curie is the older unit, based on the activity of 1 gram of radium-226, while becquerel is the modern SI unit.

1 becquerel (Bq) equals exactly 1 radioactive decay per second. It is thus a direct measure of the activity of a radioactive sample, regardless of the type of radiation produced.

No. This converter only converts activity (becquerel/curie) – i.e. how many decays occur per second. Equivalent dose (sievert) and absorbed dose (gray) are physically different quantities that also depend on radiation type, energy, and exposed tissue, and cannot be calculated from activity using a fixed factor.