Rem to Curies Converter
Convert a radiation dose in rem back to an equivalent activity in curies — with a step-by-step chain and an explanation of why these units measure different things.
Use the Rem to Curies Converter
Input Dose
Enter a dose value and select a radiation type, then click Convert.
Summary
The rem (roentgen equivalent man) measures biological radiation dose — how much energy is deposited in tissue, weighted by radiation type. The curie (Ci) measures radioactivity — how many atoms in a source decay per second. They describe different physical quantities, so there is no single fixed conversion number: you need a dose conversion factor (rem/Bq) that depends on the radiation type. This tool inverts that chain — rem to Sv to Bq to Ci — and shows every calculation step so you understand exactly what assumptions are being made.
How it works
- Enter a dose value in rem or millirem.
- Select the radiation type: alpha, beta, gamma, or X-ray.
- The tool converts rem to sieverts by dividing by 100 (1 rem = 0.01 Sv).
- It divides by the representative dose conversion factor (Sv/Bq) to recover becquerels.
- Finally it converts becquerels to curies using 1 Ci = 3.7 × 10¹⁰ Bq.
- All steps are displayed so you can verify each number.
Use cases
- Cross-checking historical nuclear records that mix rem dose data with curie source strengths.
- Teaching health physics students to invert the Ci → Bq → rem dose chain.
- Back-calculating approximate source activity from a measured effective dose in rem.
- Comparing how the same dose maps to very different activities across radiation types.
- Converting legacy US radiation records (rem) to SI activity (Bq / Ci) for archival.
- Quick sanity-checking dose-to-activity estimates before a full nuclide-specific calculation.