Radioactivity Converter

Convert between Becquerel, Curie, and Rutherford

Free online radioactivity unit converter supporting 3 units: Becquerel (Bq), Curie (Ci), Rutherford (Rd). Real-time conversion with high precision for nuclear physics, radiation safety, and medical applications. No registration required.

How to Use

Simple 3-step process to convert radioactivity units:

Step 1: Enter Value
Enter the radioactivity value in any unit field (Becquerel, Curie, or Rutherford)
Step 2: Automatic Conversion
All other unit fields will be automatically converted in real-time with high precision
Step 3: Copy Results
Copy the converted values you need for your radiation measurements or calculations

All conversions are performed in your browser. No data is sent to our servers.

Radioactivity Converter Tool

Becquerel (Bq)

Curie (Ci)

Rutherford (Rd)

Practical Use Cases

Radioactivity converters are essential in nuclear physics, medicine, and safety:

1. Nuclear Medicine

Medical isotopes for diagnosis and treatment. Technetium-99m: 740 MBq (20 mCi) typical dose for bone scans. Iodine-131: 150-200 mCi (5.55-7.4 GBq) for thyroid treatment. Converting between Becquerel and Curie helps understand dosage across different medical standards.

2. Radiation Safety and Monitoring

Workplace safety limits and environmental monitoring. Background radiation: ~0.1 µSv/h ≈ 100 Bq/kg for natural radioactivity. Occupational limit: 20 mSv/year. Converting units helps assess exposure risks and compliance with safety regulations (IAEA, NRC standards).

3. Nuclear Physics Research

Particle decay rates and half-life calculations. Radioactive samples measured in Becquerel (SI unit). Historical data often in Curie (older unit). 1 Ci = 3.7 × 10¹⁰ Bq represents the activity of 1 gram of radium-226. Converting enables comparison of research data across decades.

4. Food Safety and Agriculture

Food contamination limits after nuclear incidents. EU limit for Cesium-137 in food: 1250 Bq/kg. Japan post-Fukushima: 100 Bq/kg. Agricultural products monitored for Iodine-131, Cesium-134/137. Converting units helps understand international safety standards.

5. Radioactive Waste Management

Waste classification by activity level. Low-level waste: < 400 Bq/g. Intermediate-level: 400 Bq/g - 1 TBq/m³. High-level: > 1 TBq/m³. Converting between units essential for storage, transportation, and disposal planning according to international regulations.

What is Radioactivity Conversion?

Radioactivity measures the rate of nuclear decay. Different units are used in different fields and eras, making conversion essential.

Common Radioactivity Units

Becquerel (Bq) is the SI unit of radioactivity: 1 Bq = 1 decay per second. Named after Henri Becquerel. Used in modern scientific and medical contexts. Curie (Ci) is an older unit: 1 Ci = 3.7 × 10¹⁰ Bq (37 billion decays/second). Represents the activity of 1 gram of radium-226. Still used in some medical and industrial applications. Rutherford (Rd) is a legacy unit: 1 Rd = 10⁶ Bq (1 million decays/second). Rarely used today but appears in historical literature.

Why Convert Radioactivity Units?

Different countries and industries use different units. Modern science uses Becquerel (SI standard). Medical fields often use Curie (especially in the US). Historical data uses various units including Rutherford. Converting between units enables: comparison of radiation levels across different sources, understanding safety limits in different regulatory frameworks, interpreting medical dosages, and analyzing historical nuclear physics research.

Conversion Accuracy and Scale

This converter uses exact conversion factors: 1 Ci = 37,000,000,000 Bq (3.7 × 10¹⁰ Bq exactly). 1 Rd = 1,000,000 Bq (10⁶ Bq exactly). Results provided with up to 15 decimal places for scientific precision. The huge scale difference (1 Ci = 37 billion Bq) reflects the enormous number of atomic decays in radioactive materials.

Frequently Asked Questions

What is the difference between Becquerel and Curie?

Becquerel (Bq) is the modern SI unit: 1 Bq = 1 nuclear decay per second. Curie (Ci) is an older unit: 1 Ci = 37 billion Bq (3.7 × 10¹⁰ Bq). Curie was based on the activity of 1 gram of radium-226. Modern science uses Becquerel, but Curie is still used in some medical contexts (especially in the US).

How do I convert Becquerel to Curie?

Divide Becquerels by 37 billion (3.7 × 10¹⁰): Bq ÷ 37,000,000,000 = Ci. Example: 1 million Bq = 1,000,000 ÷ 37,000,000,000 = 0.000027 Ci = 27 µCi. Conversely, multiply Curie by 37 billion: 1 mCi = 0.001 Ci × 37,000,000,000 = 37,000,000 Bq = 37 MBq.

What is a safe level of radioactivity?

Background radiation: ~2-3 mSv/year (natural sources). Occupational limit: 20 mSv/year average over 5 years (IAEA). Public limit: 1 mSv/year above background. Note: Activity (Bq) ≠ Dose (Sv). Dose depends on radiation type, energy, and exposure pathway. 100 Bq of Cesium-137 in food ≠ 100 Bq of external radiation.

Why is Curie so much larger than Becquerel?

1 Curie = 37 billion Becquerel because it was defined as the activity of 1 gram of radium-226, which undergoes 37 billion decays per second. This huge number reflects the enormous activity of radioactive materials. Modern science prefers Becquerel (1 decay/second) for simplicity, using prefixes like kBq, MBq, GBq for larger activities.

What is Rutherford used for?

Rutherford (Rd) is a historical unit: 1 Rd = 1 million Bq (10⁶ Bq). Named after Ernest Rutherford. Rarely used in modern science but appears in older nuclear physics literature from the early-to-mid 20th century. It's intermediate between Becquerel and Curie in scale.

How much radioactivity is in everyday items?

Bananas: ~15 Bq (potassium-40). Smoke detector: ~30,000 Bq (americium-241). Granite countertop: 1000-4000 Bq/kg. Human body: ~4000 Bq (potassium-40, carbon-14). Brazil nuts: up to 240 Bq (radium). These are natural background sources posing minimal risk.

What radioactivity levels require special handling?

Exempt level (no regulation): < 10,000 Bq total for most isotopes. Sealed source registration: > 10 MBq (varies by isotope). Transport regulations: vary widely by isotope and physical form. Always consult local nuclear regulatory authority (NRC in US, ARPANSA in Australia, etc.) for specific requirements.

How accurate is this radioactivity converter?

This converter uses exact conversion factors: 1 Ci = 3.7 × 10¹⁰ Bq (exactly, by definition). 1 Rd = 10⁶ Bq (exactly, by definition). Results are provided with up to 15 decimal places for scientific precision. No approximations are used. The conversions are mathematically exact.