Radiation Dose

Health Physics & Radiation Metrology Standards (ICRP & BIPM)

Ionizing radiation measurement distinguishes between physical energy absorbed and biological damage:

• Absorbed Dose (Energy deposited in tissue):

• 1 Gray (Gy): 1 J/kg = 100 Rad

• 1 Rad: 0.01 Gy = 0.01 J/kg

• Equivalent / Effective Biological Dose (Damage to human tissue):

• 1 Sievert (Sv): 100 Rem = 1,000 mSv = 1,000,000 μSv

• 1 Rem: 0.01 Sv = 10 mSv = 1,000 mrem

Primary Radiation Exposure Benchmarks

• 0.1 µSv (0.0001 mSv): Eating 1 potassium-rich banana (^40K decay)

• 10.0 µSv (0.010 mSv): Dental Bitewing X-ray (4 images)

• 100.0 µSv (0.100 mSv): Commercial cross-country airline flight (cosmic rays)

• 2,400.0 µSv (2.400 mSv): Average global annual background radiation from radon, soil, and cosmic rays

• 7,000.0 µSv (7.000 mSv): Full chest CT scan with contrast

• 50,000.0 µSv (50.000 mSv): US NRC annual maximum legal occupational limit for radiation workers

• 1,000,000.0 µSv: Threshold for acute radiation sickness (ARS)

How to Use This Calculator

Enter your Radiation Dose Value (e.g. 2.4), Input Radiation Unit — choose from Millisieverts (mSv / Standard Biological Dose), Microsieverts (µSv / Low Environmental Exposure), Sieverts (Sv / High Acute Exposure), and Environmental & Medical Benchmark — choose from Custom Radiation Value, 0.1 µSv (0.0001 mSv / Eating 1 Banana), 10.0 µSv (0.010 mSv / Dental Bitewing X-Ray). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Conversion factors used in this calculator:

1 Sv = 1,000 mSv

1 Rem = 10 mSv

1 mrem = 0.01 mSv

1 Gy = 1,000 mGy

1 Rad = 10 mSv

Worked Example

A diagnostic full-body chest CT scan delivering 7.0 mSv equals 700 mrem (0.007 Sv or 7,000 µSv), approximately equal to 3 years of natural background radiation.

Understanding Your Result

Unit conversions are exact by definition within a given measurement system (e.g., 1 km = exactly 1,000 m). Cross-system conversions (metric to imperial) use defined exchange factors: 1 inch = exactly 2.54 cm; 1 pound = 0.45359237 kg. Round your converted result to match the precision of your original measurement — expressing more decimal places than your input justifies implies false accuracy. For regulatory, legal, or safety-critical applications, verify which measurement system is required by the applicable standard.