Free online calculator to convert 16 radiation activity units instantly. Includes becquerel, gigabecquerel, terabecquerel, curie, and related conversion tools.
Radiation Activity Converter
Radiation Activity Converter & Guide
Easily convert between all standard units of radioactivity (decay rate), including Becquerel [Bq], Curie [Ci], Rutherford [Rd], Disintegrations per second [dps], Disintegrations per minute [dpm], and all SI or conventional prefix multiples and submultiples.
What is Radiation Activity (Radioactivity)?
Radiation Activity (or radioactivity) measures the rate at which a radioactive substance undergoes nuclear decay per unit of time. It quantifies how unstable a radioactive source is by counting how many atomic nuclei transform or disintegrate every second.
In the International System of Units (SI):
- The SI base unit for radiation activity is the Becquerel [Bq], defined as one nuclear disintegration per second (1 Bq = 1 s-1).
- The historical and widely used non-SI unit is the Curie [Ci], originally defined relative to the decay rate of 1 gram of radium-226. Exactly, 1 Curie = 37 billion Becquerels (3.7 × 1010 Bq).
- In practical laboratory radiation measurement, activity is often reported as disintegrations per second (dps) or disintegrations per minute (dpm).
Supported Radiation-Activity Units
1. SI Becquerel Units
- Becquerel [Bq]: The SI base unit equal to 1 decay/second (1 Bq = 1 s-1).
- Millibecquerel [mBq]: 1 mBq = 0.001 Bq (1.0E-03 Bq).
- Kilobecquerel [kBq]: 1 kBq = 1,000 Bq (1.0E+03 Bq).
- Megabecquerel [MBq]: 1 MBq = 1,000,000 Bq (1.0E+06 Bq). Common in nuclear medicine imaging.
- Gigabecquerel [GBq]: 1 GBq = 1,000,000,000 Bq (1.0E+09 Bq). Used in radiotherapy sources.
- Terabecquerel [TBq]: 1 TBq = 1,000,000,000,000 Bq (1.0E+12 Bq). Used in industrial radiography and nuclear reactors.
2. Curie Series (Conventional Units)
- Curie [Ci]: 1 Ci = 37,000,000,000 Bq (3.7E+10 Bq = 37 GBq).
- Kilocurie [kCi]: 1 kCi = 37,000,000,000,000 Bq (3.7E+13 Bq = 37 TBq). Used for intense industrial irradiators.
- Millicurie [mCi]: 1 mCi = 37,000,000 Bq (3.7E+07 Bq = 37 MBq). Used in radiopharmaceuticals.
- Microcurie [µCi]: 1 µCi = 37,000 Bq (3.7E+04 Bq = 37 kBq). Standard unit for lab tracer amounts.
- Nanocurie [nCi]: 1 nCi = 37 Bq. Used in environmental radiation monitoring.
- Picocurie [pCi]: 1 pCi = 0.037 Bq (3.7E-02 Bq). Standard unit for environmental radon gas testing (pCi/L).
3. Rate & Legacy Units
- Disintegrations/second [dps, disintegrations/second]: Exactly equal to 1 Bq (1 dps = 1 Bq).
- Disintegrations/minute [dpm, disintegrations/minute]: 1 dpm = 1/60 Bq ≈ 0.0166666667 Bq.
- One/second [1/s]: Dimensional definition of decay frequency. 1/s = 1 Bq.
- Rutherford [Rd]: Historical unit defined as 1,000,000 disintegrations per second (1 Rd = 1,000,000 Bq = 1 MBq).
Unit Conversion Formulas
Use Becquerel [Bq] as the base unit for all radiation activity calculations:
1. Converting from Becquerel [Bq]
- To Curie [Ci]: Ci = Bq ÷ 37,000,000,000 (or Bq × 2.7027027e-11)
- To Microcurie [µCi]: µCi = Bq ÷ 37,000
- To Millicurie [mCi]: mCi = Bq ÷ 37,000,000
- To Picocurie [pCi]: pCi = Bq ÷ 0.037
- To Megabecquerel [MBq]: MBq = Bq × 0.000001
- To Gigabecquerel [GBq]: GBq = Bq × 1.0E-09
- To Rutherford [Rd]: Rd = Bq × 0.000001
- To Disintegrations/minute [dpm]: dpm = Bq × 60
2. Converting to Becquerel [Bq]
- From Curie [Ci]: Bq = Ci × 37,000,000,000
- From Kilocurie [kCi]: Bq = kCi × 37,000,000,000,000
- From Millicurie [mCi]: Bq = mCi × 37,000,000
- From Microcurie [µCi]: Bq = µCi × 37,000
- From Nanocurie [nCi]: Bq = nCi × 37
- From Picocurie [pCi]: Bq = pCi × 0.037
- From Rutherford [Rd]: Bq = Rd × 1,000,000
- From Disintegrations/minute [dpm]: Bq = dpm ÷ 60 (or dpm × 0.0166666667)
Radiation Activity Conversion Table
The table below provides equivalent activity values relative to 1 Becquerel [Bq]:
| Unit Name | Symbol | Equivalent in Becquerel [Bq] | Scientific / Exact Value |
|---|---|---|---|
| Millibecquerel | mBq | 0.001 Bq | 1.0E-03 Bq |
| Picocurie | pCi | 0.037 Bq | 3.7E-02 Bq |
| Disintegrations/minute | dpm | 0.0166666667 Bq | (1/60) Bq |
| Becquerel | Bq | 1 Bq | 1.0E+00 Bq |
| One/second | 1/s | 1 Bq | 1.0E+00 Bq |
| Disintegrations/second | dps | 1 Bq | 1.0E+00 Bq |
| Nanocurie | nCi | 37 Bq | 3.7E+01 Bq |
| Kilobecquerel | kBq | 1,000 Bq | 1.0E+03 Bq |
| Microcurie | µCi | 37,000 Bq | 3.7E+04 Bq |
| Megabecquerel | MBq | 1,000,000 Bq | 1.0E+06 Bq |
| Rutherford | Rd | 1,000,000 Bq | 1.0E+06 Bq |
| Millicurie | mCi | 37,000,000 Bq | 3.7E+07 Bq |
| Gigabecquerel | GBq | 1,000,000,000 Bq | 1.0E+09 Bq |
| Curie | Ci | 37,000,000,000 Bq | 3.7E+10 Bq |
| Terabecquerel | TBq | 1,000,000,000,000 Bq | 1.0E+12 Bq |
| Kilocurie | kCi | 37,000,000,000,000 Bq | 3.7E+13 Bq |
Step-by-Step Conversion Examples
Example 1: Convert 5 Millicurie [mCi] to Megabecquerel [MBq]
Step 1 (Convert mCi to Bq): 5 mCi × 37,000,000 = 185,000,000 Bq
Step 2 (Convert Bq to MBq): 185,000,000 Bq ÷ 1,000,000 = 185 MBq
Result: 5 mCi is equal to 185 MBq.
Example 2: Convert 120,000 Disintegrations/minute [dpm] to Microcurie [µCi]
Step 1 (Convert dpm to Bq): 120,000 dpm ÷ 60 = 2,000 Bq
Step 2 (Convert Bq to µCi): 2,000 Bq ÷ 37,000 = 0.054054 µCi
Result: 120,000 dpm is equal to approximately 0.0541 µCi (or 54.05 nCi).
Frequently Asked Questions (FAQ)
Q1. Why is 1 Curie defined as 37 billion Becquerels?
The Curie (Ci) was originally defined in 1910 as the activity of 1 gram of radium-226. When precise measurements established that 1 g of Ra-226 decays at approximately 3.7 × 1010 disintegrations per second, the International Commission on Radiation Units (ICRU) standardized 1 Ci as exactly 3.7 × 1010 Bq.
Q2. What is the difference between dps and dpm?
Disintegrations per second (dps) counts nuclear decays over 1 second (1 dps = 1 Bq). Disintegrations per minute (dpm) counts decays over 60 seconds (1 dpm = 1/60 Bq). Geiger counters and radiation detectors frequently report raw counts in dpm.
Q3. What is a Rutherford [Rd]?
The Rutherford (symbol: Rd) is a legacy unit of radioactivity introduced by Ernest Rutherford in 1946. It is defined as exactly 1,000,000 disintegrations per second (1 MBq). Although less common today, it remains part of historical radiation literature.
