Home › Free tools › Ci ↔ Bq converter

Curie–becquerel activity converter

Type an activity in any unit to see it in every other unit at once.

Runs in your browser. Nothing you enter is sent or saved.

The exact relationships

• 1 curie (Ci) = 3.7 × 10¹⁰ becquerels (Bq), exactly, by definition
• 1 mCi = 37 MBq · 1 µCi = 37 kBq · 1 nCi = 37 Bq
• 1 Bq = 1 disintegration per second = 60 disintegrations per minute (dpm)
• 1 µCi = 2.22 × 10⁶ dpm

Questions

Why do U.S. regulations use curies?

NRC and Agreement State rules are written in curies, and most also give the SI value in becquerels. For example, the sealed-source leak-test action level is 0.005 µCi (185 Bq).

How do I turn wipe-test counts into activity?

Divide net counts per minute by the counter's efficiency to get dpm, then convert. The leak test calculator does it in one step.

More free tools