Radiation Unit Converter

Convert between different radiation measurement units including Sieverts, Grays, Rads, Rems, Becquerels, and Curies.

Accurate radiation unit conversion tool for medical professionals, scientists, and safety officers. Convert absorbed dose, equivalent dose, and activity measurements between international and traditional units.

Examples

Click on any example to load it into the converter.

Medical X-Ray Dose

Medical

Typical chest X-ray equivalent dose in Sieverts.

Value: 0.1

From Unit: Sieverts (Sv)

Nuclear Medicine Activity

Nuclear

Common diagnostic radionuclide activity in Becquerels.

Value: 37000000000

From Unit: Becquerels (Bq)

Annual Background Radiation

Safety

Average annual background radiation exposure in Sieverts.

Value: 0.003

From Unit: Sieverts (Sv)

Industrial Gamma Source

Industrial

Industrial gamma source activity in Curies.

Value: 1

From Unit: Curies (Ci)

Other Titles
Understanding Radiation Unit Converter: A Comprehensive Guide
Master the conversion between different radiation measurement units used in medicine, science, and safety applications. Learn the relationships between absorbed dose, equivalent dose, and activity measurements.

What is Radiation Unit Conversion?

  • Understanding Radiation Measurements
  • Types of Radiation Units
  • Why Unit Conversion Matters
Radiation unit conversion is the process of translating measurements between different systems used to quantify radiation exposure, absorbed dose, and radioactivity. This conversion is essential in medical imaging, nuclear medicine, radiation therapy, environmental monitoring, and safety assessments. Different countries and fields use various unit systems, making conversion tools indispensable for accurate communication and decision-making in radiation-related applications.
The Three Main Categories of Radiation Units
Radiation measurements fall into three primary categories: absorbed dose (energy deposited per unit mass), equivalent dose (biological effect of radiation), and activity (rate of radioactive decay). Absorbed dose units include Grays (Gy) and Rads (rad), while equivalent dose units include Sieverts (Sv) and Rems (rem). Activity units include Becquerels (Bq) and Curies (Ci). Each category serves different purposes in radiation science and medicine.
International vs Traditional Units
The International System of Units (SI) uses Grays, Sieverts, and Becquerels as the standard units, while traditional units include Rads, Rems, and Curies. Many countries have transitioned to SI units, but traditional units remain in use in some regions, particularly the United States. Understanding both systems and their relationships is crucial for international collaboration and regulatory compliance.
The Critical Role of Accurate Conversion
Incorrect radiation unit conversion can have serious consequences in medical treatment, safety assessments, and regulatory compliance. A simple decimal error can result in significant over or under-dosing in radiation therapy, or incorrect safety evaluations in nuclear facilities. This makes reliable conversion tools essential for professionals working with radiation.

Key Unit Relationships:

  • 1 Gray (Gy) = 100 Rads (rad) - absorbed dose conversion
  • 1 Sievert (Sv) = 100 Rems (rem) - equivalent dose conversion
  • 1 Becquerel (Bq) = 2.7 × 10⁻¹¹ Curies (Ci) - activity conversion
  • Equivalent dose = Absorbed dose × Radiation weighting factor

Step-by-Step Guide to Using the Radiation Converter

  • Input Preparation
  • Unit Selection
  • Result Interpretation
Using the radiation unit converter effectively requires understanding your measurement type, selecting appropriate units, and interpreting results in context. This systematic approach ensures accurate conversions and meaningful results for your specific application.
1. Identify Your Measurement Type
First, determine whether you're working with absorbed dose (energy deposited), equivalent dose (biological effect), or activity (decay rate). Absorbed dose measurements use Grays or Rads, equivalent dose uses Sieverts or Rems, and activity uses Becquerels or Curies. This classification determines which conversion factors apply and helps you select the appropriate source unit.
2. Enter Your Value with Precision
Input your numerical value carefully, ensuring you use the correct number of significant figures. Radiation measurements often involve very small or very large numbers, so precision is crucial. For example, medical doses might be in millisieverts (mSv) or microsieverts (μSv), while activity measurements might be in megabecquerels (MBq) or gigabecquerels (GBq).
3. Select the Appropriate Source Unit
Choose the unit that matches your input value. If your measurement is in Sieverts, select 'Sieverts (Sv)'. If it's in traditional units like Rems, select 'Rems (rem)'. The converter will automatically provide conversions to all related units in the same category, plus relevant units from other categories when applicable.
4. Interpret Results in Context
Review all converted values to understand the relationships between different units. Pay attention to the magnitude differences - for example, 1 Curie equals 37 billion Becquerels, showing why different units are used for different applications. Consider which units are most appropriate for your specific use case and reporting requirements.

Common Conversion Scenarios:

  • Medical imaging: Convert patient doses from mSv to mrem for US reporting
  • Nuclear medicine: Convert activity from MBq to mCi for dose calculations
  • Radiation therapy: Convert absorbed dose from Gy to rad for treatment planning
  • Environmental monitoring: Convert background radiation from μSv to mrem

Real-World Applications and Use Cases

  • Medical Applications
  • Industrial and Safety
  • Research and Education
Radiation unit conversion finds applications across diverse fields, from life-saving medical procedures to environmental protection and scientific research. Understanding these applications helps users select appropriate units and interpret results correctly for their specific needs.
Medical Imaging and Nuclear Medicine
In medical imaging, radiologists and nuclear medicine physicians regularly convert between units for patient dose reporting, equipment calibration, and international collaboration. CT scans typically deliver 1-10 mSv, while nuclear medicine procedures might involve activities of 100-1000 MBq. Converting between Sieverts and Rems is common when working with international colleagues or regulatory bodies that use different unit systems.
Radiation Therapy and Oncology
Radiation therapy requires precise dose calculations, often involving conversions between Grays and Rads. Treatment planning systems may use different units, and oncologists need to communicate doses clearly to patients and other healthcare providers. Typical therapeutic doses range from 20-80 Gy, with fractionated treatments delivering 1.8-2.0 Gy per session.
Industrial and Safety Applications
Industrial radiography, nuclear power plants, and radiation safety programs all require unit conversion for regulatory compliance, safety assessments, and international standards. Workers in these fields need to understand both SI and traditional units, as different countries and organizations may use different systems. Safety limits are often expressed in Sieverts or Rems, while source activities might be in Becquerels or Curies.
Environmental Monitoring and Research
Environmental scientists monitor background radiation, nuclear accidents, and natural radioactivity using various units. Converting between units is essential for comparing data from different sources, complying with international reporting standards, and communicating findings to diverse audiences. Research publications often require results in SI units, while public communication might use traditional units.

Typical Dose Ranges by Application:

  • Chest X-ray: 0.1 mSv (0.01 rem)
  • CT scan: 1-10 mSv (0.1-1 rem)
  • Annual background: 3 mSv (0.3 rem)
  • Radiation therapy: 20-80 Gy (2000-8000 rad)
  • Nuclear medicine: 100-1000 MBq (2.7-27 mCi)

Common Misconceptions and Best Practices

  • Unit Confusion
  • Precision and Accuracy
  • Regulatory Compliance
Avoiding common errors in radiation unit conversion requires understanding the relationships between units, maintaining appropriate precision, and following regulatory requirements. These best practices ensure accurate results and prevent potentially serious consequences.
Myth: All Radiation Units Are Interchangeable
This misconception can lead to serious errors. Grays and Sieverts are not the same - Grays measure absorbed dose (energy deposited), while Sieverts measure equivalent dose (biological effect). The conversion depends on the type of radiation and tissue involved. Similarly, Becquerels measure activity (decay rate), not dose, so they cannot be directly converted to dose units without additional information about the radiation type and exposure conditions.
Precision and Significant Figures
Radiation measurements often involve very small or large numbers, making precision crucial. Maintain appropriate significant figures throughout calculations - don't round intermediate results unnecessarily. For medical applications, dose calculations typically require precision to 2-3 significant figures, while research applications might require higher precision. Always verify that your converted results make sense in the context of typical values for your application.
Regulatory and Reporting Requirements
Different countries and organizations have specific requirements for radiation unit reporting. The International Commission on Radiological Protection (ICRP) recommends SI units, while some US agencies still use traditional units. Medical facilities often need to report in both systems for international collaboration. Always verify the required units for your specific application and maintain documentation of your conversion methods.
Quality Assurance and Verification
Implement quality assurance procedures for radiation unit conversions, especially in medical and safety applications. Double-check conversions using multiple methods, verify results against known relationships, and maintain records of conversion factors used. Consider using certified conversion tools and regularly updating your knowledge of unit relationships and regulatory requirements.

Quality Assurance Checklist:

  • Verify unit relationships using known conversion factors
  • Check that results fall within expected ranges for your application
  • Document conversion methods and factors used
  • Use appropriate significant figures for your application
  • Confirm regulatory requirements for unit reporting

Mathematical Derivation and Conversion Factors

  • Conversion Formulas
  • Radiation Weighting Factors
  • Practical Calculations
Understanding the mathematical relationships between radiation units provides insight into their physical meaning and helps verify conversion accuracy. These relationships are based on fundamental physics principles and international standards.
Absorbed Dose Conversions
The Gray (Gy) is the SI unit for absorbed dose, defined as 1 joule of energy deposited per kilogram of material. The traditional unit is the Rad (rad), where 1 Gy = 100 rad. This relationship is exact and based on the definition of these units. For most practical purposes, the conversion is straightforward: multiply Grays by 100 to get Rads, or divide Rads by 100 to get Grays.
Equivalent Dose and Radiation Weighting Factors
Equivalent dose (measured in Sieverts or Rems) accounts for the biological effectiveness of different types of radiation. The conversion from absorbed dose to equivalent dose uses radiation weighting factors: Equivalent Dose = Absorbed Dose × Radiation Weighting Factor. For X-rays, gamma rays, and beta particles, the weighting factor is 1, so 1 Gy = 1 Sv. For alpha particles, the weighting factor is 20, so 1 Gy = 20 Sv.
Activity Conversions
Activity measures the rate of radioactive decay, with the Becquerel (Bq) as the SI unit (1 decay per second) and the Curie (Ci) as the traditional unit (3.7 × 10¹⁰ decays per second). The conversion is 1 Ci = 3.7 × 10¹⁰ Bq. This large conversion factor explains why different units are used for different applications - medical doses might be in MBq while environmental contamination might be in Bq.
Practical Calculation Examples
For a typical chest X-ray delivering 0.1 mSv: Convert to mrem: 0.1 mSv × 100 = 10 mrem. Convert to μSv: 0.1 mSv × 1000 = 100 μSv. For a nuclear medicine procedure with 370 MBq activity: Convert to mCi: 370 MBq ÷ 37 = 10 mCi. These calculations demonstrate the importance of understanding unit relationships and using appropriate conversion factors.

Key Conversion Relationships:

  • 1 Gy = 100 rad (exact conversion)
  • 1 Sv = 100 rem (exact conversion)
  • 1 Ci = 3.7 × 10¹⁰ Bq (exact conversion)
  • For X-rays and gamma rays: 1 Gy = 1 Sv (weighting factor = 1)
  • For alpha particles: 1 Gy = 20 Sv (weighting factor = 20)