Radioactivity
BqtoCi
Convert becquerels (Bq) to curies (Ci).
Factor1 Bq = 2.702703e-11 Ci
Converter
Bq
Accepts numbers or expressions, e.g. 150 + 14.7
Result
Ci
Rendered to 6 significant figures.
Formula
Formula
Ci = Bq × 2.702703e-11
Multiply any value in becquerels by 2.702703e-11 to obtain the value in curies.
Worked example
Convert 1e+9 Bq to Ci.
- 01Start with 1e+9 Bq.
- 02Multiply by the conversion factor: 1e+9 × 2.702703e-11 = 0.027027 Ci.
Result1e+9 Bq = 0.027027 Ci
Conversion table
| Bq | Ci |
|---|---|
| 1 | 2.7027e-11 |
| 2 | 5.4054e-11 |
| 5 | 1.3514e-10 |
| 10 | 2.7027e-10 |
| 20 | 5.4054e-10 |
| 50 | 1.3514e-9 |
| 100 | 2.7027e-9 |
| 200 | 5.4054e-9 |
| 500 | 1.3514e-8 |
| 1000 | 2.7027e-8 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from Bq to Ci?
1 Bq equals 2.702703e-11 Ci. To convert, multiply the value in becquerels by 2.702703e-11.
How do I convert 1 Bq to Ci?
1 Bq = 2.7027e-11 Ci. For any value, multiply by 2.702703e-11.
How do I convert Ci back to Bq?
Divide by the same factor — or equivalently, multiply by 3.7e+10. So 1 Ci = 3.7e+10 Bq.
When would I need to convert becquerel to curie?
Radioactivity (activity) conversions between Bq and Ci are routine in health physics, nuclear medicine ordering, environmental monitoring, radiopharmacy and reactor/accelerator-source documentation. The becquerel (Bq) is the SI unit; the curie (Ci) is the legacy unit (1 Ci ≡ 3.7×10¹⁰ Bq exactly). This category is strictly activity (decays per second) — it does NOT cover absorbed dose (Gy, rad), dose equivalent (Sv, rem), exposure or dose rate, all of which are different physical quantities and live in separate categories.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).