Absorbed Radiation Dose Converter

Convert absorbed radiation dose values among common SI, metric and customary units. Absorbed dose is energy deposited by ionizing radiation per unit mass. The gray is the SI unit and equals one joule per kilogram.

ValueEnter zero or a positive value; scientific notation is accepted.Convert fromGray (Gy)Milligray (mGy)Microgray (µGy)Rad (rad)Erg per gram (erg/g)Convert toGray (Gy)Milligray (mGy)Microgray (µGy)Rad (rad)Erg per gram (erg/g)

Convert

Converted value0.01 Gy

SI-base value0.01 Gy

Multiply by0.01

The displayed results apply to the default example. Enable JavaScript to convert other values.

How to use this converter

1. Enter the absorbed radiation dose value.
2. Select its current unit and the unit you want.
3. Select Convert. The page shows the converted value, the SI-base value and the direct multiplication factor.

Conversion formula

Converted value = entered value × source-to-SI factor ÷ target-to-SI factor.

Every option is represented by its factor to gray (Gy). This one-base method keeps reciprocal conversions consistent. Calculations run in your browser, and old results are hidden when an input changes or validation fails.

Worked example

Convert 1 rad to Gy. Multiply by 0.01; the result is 0.01 Gy. The same input equals 0.01 Gy in the SI-base unit.

Accuracy and limitations

Absorbed dose is not the same as equivalent or effective dose and cannot by itself determine biological risk. Radiation decisions require qualified professionals.

The calculator retains more digits internally than it displays. Round the final value to the precision supported by your measurement. Very large and very small answers may use scientific notation.

Frequently asked questions

How many grays are in 100 rad?

One rad equals 0.01 gray, so 100 rad equals 1 gray.

Can I reverse the conversion?

Yes. Swap the From and To selections. Because both units use the same SI base, the reverse factor is the reciprocal of the forward factor.

Why was my entry rejected?

Use digits with an optional decimal point or scientific notation. Blank values, commas, fractions, words and non-finite entries are rejected. Negative values are rejected because this converter treats the quantity as a magnitude.

Review notes and sources

Reviewed October 4, 2026. The conversion factors, default example, zero or signed boundary behavior, invalid-input handling and recovery after an error were checked. Factors follow SI definitions and published conversion guidance from the NIST Guide to the SI and the BIPM SI Brochure. Explanations and examples are original.

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