Convert Curies to Becquerels (Ci to Bq)
1 curie (Ci) = 37000000000 becquerels (Bq). 1 Bq = 2.702702703 × 10⁻¹¹ Ci. Example: 1 Ci = 1 × 37000000000 = 37000000000 Bq.
Also searched as Ci to Bq, curies to becquerels, curie to becquerel conversion and how many Bq in a curie.
1 Ci = 37000000000 Bq
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk curie to becquerel converter to paste a column from Excel.
How to Convert Curie to Becquerel
- 1 Ci = 37000000000 Bq
- 1 Bq = 2.702702703 × 10⁻¹¹ Ci
- Example: convert 1 Ci to Bq: 1 Ci = 1 × 37000000000 Bq = 37000000000 Bq
Formula
Bq = Ci × 37000000000
Derivation from SI units:
- 1 Ci = 3.7 × 10¹⁰ Bq exactly (originally the activity of 1 g of radium-226).
- 1 Bq = 1 decay per second (s⁻¹).
Both units are defined exactly, so the factor is exact. Curie definition: curie; Becquerel definition: becquerel.
Worked examples
- 1 Ci is 37000000000 Bq.
1 Ci × 37000000000 = 37000000000 Bq - A 0.5 Ci source is 18500000000 Bq.
0.5 Ci × 37000000000 = 18500000000 Bq
Curie to Becquerel conversion table
| Curies (Ci) | Becquerels (Bq) |
|---|---|
| 0.1 Ci | 3700000000 Bq |
| 0.5 Ci | 18500000000 Bq |
| 1 Ci | 37000000000 Bq |
| 2 Ci | 74000000000 Bq |
| 5 Ci | 185000000000 Bq |
| 10 Ci | 370000000000 Bq |
| 20 Ci | 740000000000 Bq |
| 50 Ci | 1850000000000 Bq |
| 100 Ci | 3700000000000 Bq |
| 1000 Ci | 37000000000000 Bq |
Where it's used
Source activities in curies from US licences, older papers and sealed-source labels are converted to becquerels, the SI unit used by regulators outside the US. Multiply by 3.7 × 10¹⁰.
Curie to other radioactivity units
| Conversion | 1 Ci equals |
|---|---|
| curie to becquerel | 37000000000 Bq |
| curie to megabecquerel | 37000 MBq |
| curie to millicurie | 1000 mCi |
| curie to picocurie | 1000000000000 pCi |
| curie to kilobecquerel | 37000000 kBq |
| curie to gigabecquerel | 37 GBq |
| curie to microcurie | 1000000 µCi |
| curie to disintegration per minute | 2220000000000 dpm |
Show 3 more units
| curie to terabecquerel | 0.037 TBq |
|---|---|
| curie to nanocurie | 1000000000 nCi |
| curie to rutherford | 37000 Rd |
Frequently asked questions
How many becquerels are in a curie?
Exactly 3.7 × 10¹⁰: the curie was defined from the activity of one gram of radium-226, so 1 Ci = 37000000000 Bq.
Why are curies so large?
A curie is the activity of a gram of radium, enough to need heavy shielding. Everyday quantities are in mCi, µCi or pCi.
How many becquerels are in 1 curie?
1 Ci = 37000000000 Bq.
How do I convert curies to becquerels?
Multiply the value in Ci by 37000000000. For example, 1 Ci × 37000000000 = 37000000000 Bq.
Is the Ci to Bq conversion exact?
Yes. Both units are defined exactly, and 1 Ci is exactly 37000000000 Bq.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "curie".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (becquerel, gray, sievert, lux) and Table 2 (candela).
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Curies to Becquerels (Ci to Bq). Retrieved October 25, 2026, from https://scientificconverters.com/radioactivity/curies-to-becquerels/
IEEE
Scientific Converters, "Convert Curies to Becquerels (Ci to Bq)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/radioactivity/curies-to-becquerels/