Convert Curies to Millicuries

Convert Curies (Ci) to Millicuries (mCi) instantly and accurately.

Curies (Ci)
Millicuries (mCi)

Conversion Formula

mCi = Ci × 1000

About Curies

The curie (Ci) equals exactly 3.7 × 10¹⁰ Bq = 37 GBq, originally defined as the activity of 1 g of ²²⁶Ra. Still widely used in the US: ⁶⁰Co teletherapy sources are 5000-15000 Ci; ¹³⁷Cs blood irradiators are 1000-40000 Ci; NRC source licences for industrial radiography cite Ci limits. 1 Ci = 3.7 × 10¹⁰ Bq.

About Millicuries

The millicurie (mCi) equals 3.7 × 10⁷ Bq = 37 MBq. The primary clinical nuclear medicine unit in the US: ¹⁸F-FDG PET doses are 8-15 mCi; ⁹⁹mTc cardiac stress tests use 25-35 mCi; ¹³¹I hyperthyroidism therapy uses 5-30 mCi. US pharmacopeia and NRC regulations specify doses in mCi. 1 mCi = 3.7 × 10⁷ Bq.

Quick Reference Table

Curies (Ci)Millicuries (mCi)
1 Ci1000 mCi
2 Ci2000 mCi
5 Ci5000 mCi
10 Ci10000 mCi
25 Ci25000 mCi
50 Ci50000 mCi
100 Ci100000 mCi

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