Radiation Converter

How to Convert Radiation Dose Units

Radiation dose units measure how much energy radiation deposits in tissue or the biological effect of that exposure. Absorbed dose (gray and rad) quantifies the physical energy deposited per unit mass. Equivalent dose (sievert and rem) accounts for the biological effectiveness of different radiation types. Understanding these units is essential for radiation safety, medical imaging, nuclear medicine, and environmental monitoring.

Our radiation converter handles both absorbed dose units (gray, milligray, rad) and equivalent dose units (sievert, millisievert, microsievert, rem, banana equivalent dose). Select the dose type, enter a value, and see conversions across all related units.

For activity-based calculations, try our Radioactive Activity Calculator.

Absorbed Dose Conversions

Absorbed dose measures energy deposited by ionizing radiation per kilogram of tissue:

$$1 \text{ Gy} = 100 \text{ rad}$$

$$1 \text{ mGy} = 0.001 \text{ Gy} = 0.1 \text{ rad}$$

The gray (Gy) is the SI unit. One gray equals one joule of radiation energy absorbed per kilogram of matter. The rad (radiation absorbed dose) is the older CGS unit, still used in some US medical and industrial contexts.

Equivalent Dose Conversions

Equivalent dose adjusts absorbed dose for the biological impact of different radiation types using a radiation weighting factor:

$$1 \text{ Sv} = 100 \text{ rem}$$

$$1 \text{ mSv} = 0.001 \text{ Sv}$$

$$1 \text{ µSv} = 0.000001 \text{ Sv}$$

For beta, gamma, and X-ray radiation, 1 Gy of absorbed dose equals 1 Sv of equivalent dose (weighting factor of 1). For alpha particles and neutrons, the weighting factor is higher, so the same absorbed dose produces a greater equivalent dose.

Common Dose Reference Values

• Chest X-ray: approximately 0.1 mSv
• CT scan (abdomen): approximately 10 mSv
• Natural background radiation: approximately 3 mSv per year
• Occupational limit (US): 50 mSv per year
• Banana equivalent dose: approximately 0.1 µSv per banana