Radiation Dose Converter
Convert between different radiation dose units including grays, rads, sieverts, rems, and roentgens
Conversion Settings
Absorbed dose - energy deposited per unit mass
Equivalent dose - biological effect weighted
Used only when converting between absorbed dose (Gy, rad) and equivalent dose (Sv, rem): Sv = Gy × w_R (ICRP 103). Default is photons (w_R = 1), so 1 Gy = 1 Sv only for photons and electrons. Neutron values use the ICRP 103 energy function.
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Conversion Result
Conversion result will appear here
Enter a value and click "Convert" to start
⚠️ Important Safety Information:
This tool is for educational and reference purposes only. Always follow proper radiation safety protocols and consult qualified health physicists for dose assessments.
Unit Types:
- • Absorbed Dose: Energy deposited (Gray, rad)
- • Equivalent Dose: Biological effect (Sievert, rem)
- • Exposure: Ionization in air (Roentgen)
Reference Limits:
- • Annual dose limit (public): 1 mSv
- • Annual dose limit (workers): 20 mSv
- • Chest X-ray: ~0.1 mSv
- • CT scan: ~10 mSv
About Radiation Dose Converter
A comprehensive radiation dose converter tool that allows you to convert between various radiation dose measurement units. Whether you're working in radiation safety, medical physics, nuclear medicine, or health physics, this tool provides accurate conversions between grays, rads, sieverts, rems, roentgens, and their sub-units for both absorbed dose and equivalent dose measurements.
Why use a Radiation Dose Converter?
Radiation dose conversion is critical in radiation protection, medical physics, and nuclear safety. Different units measure different aspects of radiation dose - absorbed dose (gray, rad) and equivalent dose (sievert, rem), with exposure measured in roentgens. This tool ensures accurate dose calculations for safety assessments, medical procedures, and regulatory compliance.
Who is it for?
This tool is perfect for health physicists, medical physicists, radiation safety officers, nuclear medicine technologists, radiologic technologists, students studying radiation physics, and professionals working with ionizing radiation who need accurate dose unit conversions.
How to use the tool
Enter the radiation dose value you want to convert in the input field
Select the source unit from the dropdown (grays, sieverts, etc.)
Choose the target unit you want to convert to
Pick the radiation type (w_R) if you convert between Gy/rad/R and Sv/rem, then click 'Convert' to see the result
Use the swap button to quickly reverse the conversion direction
Copy the result or use the clear button to start over
Frequently Asked Questions
How do I convert radiation dose units?
Enter the source value, pick the 'from' and 'to' units, and click Convert to see the result. Supports Sv (sievert, SI), mSv, μSv, rem (legacy US), Gy (gray, absorbed dose), rad (legacy), R (roentgen). When you convert between absorbed/exposure units (Gy, rad, R) and equivalent-dose units (Sv, rem), pick the radiation type; the tool multiplies by its ICRP 103 weighting factor w_R. Copy the converted value to clipboard. Conversion runs entirely in your browser — values never leave the device. Results are shown to up to 12 significant digits with trailing zeros removed; there is no precision setting.
What radiation dose units does this converter support?
Sv (sievert, SI), mSv, μSv, rem (legacy US), Gy (gray, absorbed dose), rad (legacy), R (roentgen). The set covers SI base and derived units, common imperial/US-customary units, and domain-specific units where relevant. SI prefixes (k, M, G, m, μ, n) apply where applicable. For any unit not in the list that you need converted, mention it via feedback — the unit set evolves based on user requests.
How accurate is the radiation dose conversion?
Conversions use the internationally-defined factors where they exist; the result is rounded to 12 significant digits for display. Sv = J/kg with biological weighting. The tool uses the ICRP 103 radiation weighting factors w_R (photons and electrons 1, protons 2, alpha particles 20, neutrons energy-dependent at five fixed energies) and applies w_R only when converting between absorbed/exposure units (Gy, rad, R) and Sv/rem. Roentgen is converted to gray using an approximate air value (0.00877 Gy per R). Output is rounded to 12 significant digits for display, and there is no setting to change that.
What's the formula to convert rem to sievert (Sv)?
Sv = rem / 100. Medical imaging dose estimation (X-ray, CT, PET — patient dose in mSv), radiation safety in nuclear and industrial settings (workplace limits typically 20 mSv/year), background-radiation comparisons (μSv/h from radon, cosmic rays). For other radiation dose-unit pairs, the tool applies the appropriate exact conversion factor automatically — no manual formula needed. Results are rounded to 12 significant digits, which is more than engineering specs typically need.
What's the key accuracy caveat for radiation dose conversion?
**Sievert (Sv) measures equivalent dose** (radiation × biological effectiveness weighting) — the unit used for health and safety. Gray (Gy) measures absorbed dose (energy per kg, no weighting). For photons (X-rays, gamma), 1 Sv ≈ 1 Gy; for alpha radiation, 1 Gy ≈ 20 Sv (alpha is far more biologically harmful). Legacy units: rem (= 0.01 Sv) and rad (= 0.01 Gy). **Background radiation** averages ~2-3 mSv/year worldwide; CT scan ~5-15 mSv; chest X-ray ~0.1 mSv.
What's a common real-world use case for radiation dose conversion?
Medical imaging dose estimation (X-ray, CT, PET — patient dose in mSv), radiation safety in nuclear and industrial settings (workplace limits typically 20 mSv/year), background-radiation comparisons (μSv/h from radon, cosmic rays).
What radiation dose units are commonly confused?
**Sv vs Gy** — equivalent dose vs absorbed dose; biological effectiveness weighting matters. **rem vs Sv** — legacy US vs SI; 1 Sv = 100 rem. **'Activity'** (becquerel) vs 'dose' (sievert) — activity is decays per second; dose is what's absorbed.
How do I handle very large or very small radiation dose values?
Use SI prefixes for clean scaling: kilo (10³), mega (10⁶), giga (10⁹), milli (10⁻³), micro (10⁻⁶), nano (10⁻⁹). For very large or very small results, the tool switches to exponent notation (e.g. 1.23e15) at 1e15 and above or below 1e-9. Sv = J/kg with biological weighting. The tool uses the ICRP 103 radiation weighting factors w_R (photons and electrons 1, protons 2, alpha particles 20, neutrons energy-dependent at five fixed energies) and applies w_R only when converting between absorbed/exposure units (Gy, rad, R) and Sv/rem. Roentgen is converted to gray using an approximate air value (0.00877 Gy per R). For data interchange, copy the value; it is shown to 12 significant digits.
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