Select Radiation Quantity
Enter Value & Units
Result
Converted: –
Scientific: –
Grouped: –
Overview
Source Activity measures decays per second:
• Bq (becquerel) = 1 disintegration/s
• Ci (curie) = 3.7×10¹⁰ Bq
Exposure: Roentgen (R) = 2.58×10⁻⁴ C/kg
Absorbed Dose:
• Gy (gray) = 1 J/kg
• rad = 0.01 Gy
Equivalent Dose:
• Sv (sievert) = 1 J/kg
• rem = 0.01 Sv
Formula & Methodology
We pivot all to the SI base then convert: \( X_{\!SI} = X_{\text{input}} \times f_{\text{from}} \) \( X_{\text{out}} = \frac{X_{\!SI}}{f_{\text{to}}} \)
Examples
- 1 Ci → Bq: 1×3.7×10¹⁰ = 3.7×10¹⁰ Bq
- 100 rad → Gy: 100×0.01 = 1 Gy
- 5 Sv → rem: 5÷0.01 = 500 rem
Use Cases
- Medical imaging: doses in mGy or mSv.
- Nuclear labs: source activity in Bq/Ci.
- Radiation protection: exposure limits in R.
Frequently Asked Questions
Why use becquerel vs curie?
Bq is SI, curie is legacy; both measure disintegration rate.
What’s the difference between gray and sievert?
Gray measures energy absorbed; sievert accounts for biological effect via weighting factors.
How is roentgen used today?
Roentgen measures ionization in air—largely replaced by coulomb/kg in modern practice.
Can I convert rad to rem directly?
Yes: 1 rad = 0.01 Gy → 0.01 Sv → 1 rem.