Radioactivity
CitoBq
Convert curies (Ci) to becquerels (Bq).
Factor1 Ci = 3.7e+10 Bq
Converter
Ci
Accepts numbers or expressions, e.g. 150 + 14.7
Result
Bq
Rendered to 6 significant figures.
Formula
Formula
Bq = Ci × 3.7e+10
Multiply any value in curies by 3.7e+10 to obtain the value in becquerels.
Worked example
Convert 1 Ci to Bq.
- 01Start with 1 Ci.
- 02Multiply by the conversion factor: 1 × 3.7e+10 = 3.7e+10 Bq.
Result1 Ci = 3.7e+10 Bq
Conversion table
| Ci | Bq |
|---|---|
| 1 | 3.7e+10 |
| 2 | 7.4e+10 |
| 5 | 1.85e+11 |
| 10 | 3.7e+11 |
| 20 | 7.4e+11 |
| 50 | 1.85e+12 |
| 100 | 3.7e+12 |
| 200 | 7.4e+12 |
| 500 | 1.85e+13 |
| 1000 | 3.7e+13 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from Ci to Bq?
1 Ci equals 3.7e+10 Bq. To convert, multiply the value in curies by 3.7e+10.
How do I convert 1 Ci to Bq?
1 Ci = 3.7e+10 Bq. For any value, multiply by 3.7e+10.
How do I convert Bq back to Ci?
Divide by the same factor — or equivalently, multiply by 2.702703e-11. So 1 Bq = 2.7027e-11 Ci.
When would I need to convert curie to becquerel?
Radioactivity (activity) conversions between Ci and Bq 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).