Why is a dose factor needed — why can't I convert Ci directly to Sv?

Curies measure activity (decays per second). Sieverts measure biological dose, which depends on how much energy the radiation deposits in tissue and how damaging that energy is. The dose conversion factor (Sv/Bq) bridges the two; it differs by radiation type and by the specific nuclide. This tool uses representative factors for illustration.

What dose conversion factors does this tool use?

Representative effective dose coefficients: alpha ≈ 2.0 × 10⁻⁷ Sv/Bq, beta ≈ 1.0 × 10⁻⁸ Sv/Bq, gamma/X-ray ≈ 3.0 × 10⁻⁹ Sv/Bq. These are order-of-magnitude estimates for ingestion; actual values depend on the specific nuclide and exposure pathway. Always consult ICRP Publication 119 or a health physicist for regulatory calculations.

What is 1 curie equal to in becquerels?

1 curie (Ci) = 3.7 × 10¹⁰ becquerels (Bq). The curie was originally defined as the activity of 1 gram of radium-226. The becquerel is the SI unit: 1 Bq = 1 disintegration per second.

Can I use this for regulatory compliance?

No. This tool is educational. Regulatory dose calculations require nuclide-specific dose coefficients, pathway modeling, and verification by a qualified health physicist. Use ICRP, NCRP, or NRC data for any compliance purpose.

Why is alpha radiation's dose factor so much higher than gamma?

Alpha particles have a radiation weighting factor (Q) of 20, versus 1 for gamma and beta. Alpha particles deposit all their energy in a very short range, causing concentrated ionization damage. However, alpha radiation is stopped by skin — it only matters when alpha emitters are inhaled or ingested.

Curies to Sieverts Converter

Convert radioactivity in curies (Ci) to radiation dose in sieverts (Sv) via becquerels, with radiation-type dose factors shown step by step.

Input Activity

Activity value

Input unit

Radiation type

Enter a value and select a radiation type, then click Convert.

Note: Dose factors shown are representative effective dose coefficients for ingestion. Actual values depend on the specific nuclide and exposure pathway. For regulatory use, consult ICRP Publication 119 or a licensed health physicist.

Summary

The curie (Ci) measures radioactivity — how many atoms decay per second. The sievert (Sv) measures biological radiation dose, accounting for how damaging a given type of radiation is to tissue. Converting between them requires two steps: first multiply curies by 3.7 × 10¹⁰ to get becquerels, then apply a dose conversion factor (Sv/Bq) that depends on the radiation type and the nuclide being considered. This tool walks through that chain transparently so you can see where every number comes from.

How it works

Enter an activity value in curies (Ci), millicuries (mCi), or microcuries (µCi).
Select the radiation type: alpha, beta, gamma, or X-ray.
The tool converts your input to becquerels using 1 Ci = 3.7 × 10¹⁰ Bq.
It then applies a representative dose conversion factor (Sv/Bq) for the selected radiation type.
Results are shown in sieverts, millisieverts, and microsieverts, with each calculation step displayed.

Use cases

Understanding how legacy curie measurements relate to modern sievert-based dose limits.
Cross-checking radiation safety calculations in a lab or research setting.
Converting historical nuclear data that still uses curie units.
Teaching or studying the Ci → Bq → Sv conversion chain in nuclear physics or radiobiology.
Estimating approximate dose from a known activity source for educational purposes.
Comparing dose across different radiation types for the same activity level.

Frequently Asked Questions

Last updated: 2026-07-14 · Reviewed by Nham Vu

Curies to Sieverts Converter

Input Activity

Dose Result

Calculation Chain

Summary

How it works

Use cases

Frequently Asked Questions

Curies to Sieverts Converter

Use the Curies to Sieverts Converter

Input Activity

Dose Result

Calculation Chain

Summary

How it works

Use cases

Frequently Asked Questions