Skip to content
CALX
Appearance

Appearance

Mode


Palette

Radioactivity and dose converter

1 Bq = 1 disintegration per second

Convert a radioactivity (becquerel, curie and their multiples), an absorbed dose (gray, rad) or an equivalent dose (sievert, rem). These three quantities answer three different questions: how many disintegrations, how much energy deposited, and what biological effect is expected.

Result2.7027E-11 Curie (Ci)

1 Becquerel (Bq) = 2.702702703E-11 Curie (Ci)

Raw value: 2.70270e-11

Scientific dossier


What the tool computes, what it assumes, where it stops being valid, and where its data comes from.

Method & formulas1 Bq = 1 disintegration per second

1 Bq = 1 disintegration per second

1 Ci = 3.7 × 10¹⁰ Bq (exactly)

1 Gy = 1 J/kg

1 Sv = 1 Gy × w_R

The becquerel counts disintegrations, the gray measures energy deposited per unit mass, and the sievert weights that deposit by the harmfulness of the radiation through a factor w_R (1 for photons and electrons, up to 20 for alpha particles). Gray and sievert share the dimension J/kg without being interchangeable.

Bq
· Becquerel (Bq)
kBq
· Kilobecquerel (kBq)
MBq
· Megabecquerel (MBq)
GBq
· Gigabecquerel (GBq)
TBq
· Terabecquerel (TBq)
Ci
· Curie (Ci)
mCi
· Millicurie (mCi)
µCi
· Microcurie (µCi)
µGy
· Microgray (µGy)
mGy
· Milligray (mGy)
Gy
· Gray (Gy)
kGy
· Kilogray (kGy)
rad
· Rad (rad)
nSv
· Nanosievert (nSv)
µSv
· Microsievert (µSv)
mSv
· Millisievert (mSv)
Sv
· Sievert (Sv)
rem
· Rem (rem)
Ci
· Non-SI unit, defined as exactly 3.7 × 10¹⁰ Bq. This value comes from a historical definition (approximate activity of one gram of radium-226), not from SI coherence.
Validity domainGoing from absorbed to equivalent dose requires the radiation weighting factor w_R, and going to effective dose additionally requires tissue weighting factors.

Going from absorbed to equivalent dose requires the radiation weighting factor w_R, and going to effective dose additionally requires tissue weighting factors. These are not unit conversions but parameterised radiation-protection calculations. A converter silently applying w_R = 1 would be right for photons and wrong by a factor of 20 for an alpha emitter. The three quantities are therefore kept separate here, and the engine refuses the crossing.