Radiation ConverterConvert between sieverts, millisieverts, microsieverts, rem, millirem, grays, and rads.

Radiation Converter
Convert between sieverts, millisieverts, microsieverts, rem, millirem, grays, and rads.
Enter dose
Type the radiation dose value.
Select units
Choose source and target radiation units.
View the result
Converted dose appears instantly.
What Is Radiation Converter?
A radiation converter translates between units measuring ionizing radiation dose. The sievert (Sv) is the SI unit of dose equivalent (biological effect), while the gray (Gy) measures absorbed dose (physical energy). The rem (roentgen equivalent man) and rad are older units still widely used in the US. For gamma and beta radiation, 1 Sv = 1 Gy numerically (quality factor Q = 1), but for alpha particles and neutrons the relationship differs. This converter handles standard unit conversions and is essential for health physics, nuclear medicine, radiation safety, and environmental monitoring.
Why Use Our Radiation Converter?
- Covers both dose equivalent (Sv/rem) and absorbed dose (Gy/rad).
- Includes micro and millisievert for everyday dose measurements.
- Essential for radiation safety professionals.
- Real-time conversion.
Common Use Cases
Health Physics
Convert occupational dose measurements between SI and legacy units.
Nuclear Medicine
Convert patient dose values between sieverts and rem.
Radiation Safety
Compare dose limits expressed in different unit systems.
Environmental Monitoring
Convert background radiation measurements between µSv and mrem.
Technical Guide
Radiation dose units: Dose Equivalent (biological effect): • 1 Sv = 1,000 mSv = 1,000,000 µSv • 1 Sv = 100 rem • 1 mSv = 100 mrem = 0.1 rem Absorbed Dose (physical energy): • 1 Gy = 100 rad • 1 Gy = 1 J/kg of tissue Relationship: Sv = Gy × Q (quality factor) • For gamma/beta: Q = 1, so 1 Sv = 1 Gy • For alpha: Q = 20, so 1 Gy of alpha = 20 Sv • For neutrons: Q = 5-20 depending on energy Typical doses: • Natural background: ~2.4 mSv/year (240 mrem/year) • Chest X-ray: ~0.02 mSv (2 mrem) • CT scan: 2-10 mSv • US occupational limit: 50 mSv/year (5 rem/year) • Acute lethal dose: ~4-5 Sv
Tips & Best Practices
- 11 Sv = 100 rem. 1 mSv = 100 mrem. These are the key conversion factors.
- 2For gamma/beta radiation: Sv and Gy are numerically equal.
- 3Average natural background radiation is about 2.4 mSv (240 mrem) per year.
- 4A single chest X-ray delivers about 0.02 mSv — very low.
Related Tools

Energy Converter
Convert between joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, BTU, and electronvolts.

Power Converter
Convert between watts, kilowatts, megawatts, horsepower, PS, BTU/h, and ft-lbf/s.

Force Converter
Convert between newtons, kilonewtons, pound-force, kilogram-force, dynes, and poundals.

Pressure Converter
Convert between Pascal, kilopascal, bar, atmosphere, PSI, mmHg, and Torr pressure units.

Length Converter
Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles instantly.

Weight Converter
Convert between milligrams, grams, kilograms, ounces, pounds, metric tons, and stones in real time.
Frequently Asked Questions
QHow do I convert rem to millisieverts?
QWhat is the difference between gray and sievert?
QWhat is a safe radiation dose?
QAre sievert and gray the same for X-rays?
QHow much radiation is a CT scan?
About Radiation Converter
Radiation Converter is a free online tool from FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration required. No ads. Just fast, reliable tools.







