Convert Curies to Megacuries

Convert Curies (Ci) to Megacuries (MCi) instantly and accurately.

Curies (Ci)
Megacuries (MCi)

Conversion Formula

MCi = Ci × 1.000000000e-6

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 Megacuries

The megacurie (MCi) equals 3.7 × 10¹⁶ Bq. Total radioactive inventory of a large nuclear power reactor core at shutdown is ~2000-10000 MCi; US atmospheric nuclear weapons tests released ~12000 MCi of ¹³¹I globally; high-level nuclear waste repositories are characterised in MCi. 1 MCi = 3.7 × 10¹⁶ Bq.

Quick Reference Table

Curies (Ci)Megacuries (MCi)
1 Ci1 × 10-6 MCi
2 Ci2 × 10-6 MCi
5 Ci5 × 10-6 MCi
10 Ci1 × 10-5 MCi
25 Ci2.5 × 10-5 MCi
50 Ci5 × 10-5 MCi
100 Ci1 × 10-4 MCi

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