Built and fact-checked by the DocNectar team — see our editorial standards
Key Features
Instant Calculation
Get accurate results in real time with our optimized algorithm.
Mobile Friendly
Fully responsive design. Works on all devices & screen sizes.
Privacy Focused
Your data stays on your device. We don't store any inputs.
100% Free
No hidden costs. This tool is completely free forever.
Radioactivity — the rate at which a radioactive sample decays — is measured in Becquerel in the SI system, but Curie remains common in medical and older nuclear physics contexts. This calculator converts between Becquerel, kilobecquerel, Curie, and millicurie.
The two systems differ enormously in scale: 1 Curie equals exactly 37 billion Becquerel, reflecting the very different historical reference points each unit was originally based on.
How it works
Enter a value, choose the unit you're converting from and to, and the calculator applies the standard conversion factor between Becquerel, kilobecquerel, Curie, and millicurie.
- Enter value.
- Enter from.
- Enter to.
- Click Calculate to see your results.
Examples
A medical isotope dose
A diagnostic dose specified as 10 millicurie converts to 370,000,000 Becquerel, showing just how large the scale difference is between the two units.
Comparing lab measurements
A lab result reported in kilobecquerel is converted to millicurie to compare against an older reference reported in the Curie-based system.
Who should use it
- Converting a medical isotope dose between Curie-based and Becquerel-based units.
- Comparing radioactivity measurements reported in different unit systems.
Industry applications
- Nuclear medicine and radiology
- Nuclear physics and radiation safety
Advantages
- Covers both SI (Becquerel) and traditional (Curie) systems plus common sub-units.
- Shows the exact conversion factor used, not just the final answer.
- No account, subscription or watermark.
Limitations
- Covers radioactivity (decay rate) only — for radiation dose equivalent, use the dedicated Radiation Dose Equivalent Converter instead.
Common mistakes to avoid
- Underestimating the scale difference between Curie and Becquerel when converting by hand.
- Confusing radioactivity (decay rate) with radiation dose, which are different physical quantities measured in different units.
Best practices
- Double-check which unit system a source actually uses before comparing values directly.
- Use kilobecquerel or millicurie for typical lab-scale quantities to keep numbers readable.
Tips
- Remember that Curie is a much larger unit than Becquerel — always double-check scale when converting by hand.
- Don't confuse this with radiation dose equivalent (Sievert/rem), which measures a different quantity entirely.