Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Becquerels to Curies
Convert Bq to Ci instantly, then review the formula, assumptions, and rounding guidance.
Radiation unitsInstant result
Decimals
Formula result = input × 1 ÷ 37000000000. 1 Bq = 0 Ci
Common examples
One value, several units
Kilobecquerels0.001 kBq
Megabecquerels0 MBq
Curies0 Ci
Millicuries0 mCi
Conversion table
| Bq | Ci |
|---|---|
| 1 Bq | 0 Ci |
| 2 Bq | 0 Ci |
| 5 Bq | 0 Ci |
| 10 Bq | 0 Ci |
| 25 Bq | 0 Ci |
| 50 Bq | 0 Ci |
| 100 Bq | 0 Ci |
Conversion chart
1 Bq0 Ci
5 Bq0 Ci
10 Bq0 Ci
25 Bq0 Ci
50 Bq0 Ci
Worked example
1 curie equals exactly 3.7 × 10¹⁰ becquerels.
Unit definition
Becquerels (Bq) One becquerels equals 1 becquerel.
Unit history
Becquerels is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert Bq to becquerel.
3. Convert the base value to Ci and apply your display precision.
Understand the result before using it
Becquerels to Curies converts a value measured in Becquerels (Bq) into the equivalent value in Curies (Ci). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 1 ÷ 37000000000
Assumptions
- Becquerels and Curies represent the same radioactivity quantity.
- The input is expressed in Bq; the output is expressed in Ci.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 Bq = 0.000000000027027027027 Ci. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a Bq measurement in a document that expects Ci.
- Compare a becquerels value with a value reported in curies.
- Check the Bq-to-Ci arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Absorbed dose, equivalent dose, and activity describe different radiation quantities and are not interchangeable.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Becquerels to Curies?
result = input × 1 ÷ 37000000000 Using the displayed relationship, 1 Bq equals 0.000000000027027027027 Ci.
How many Curies are in one Becquerels?
One Becquerels is 0.000000000027027027027 Curies. The displayed digits may be rounded.
Can I reverse the Bq to Ci conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts Ci back to Bq.
Is the Becquerels to Curies result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.