Radiation (Absorbed Dose) Converter
Convert any radiation (absorbed dose) unit to another with this free radiation (absorbed dose) converter. It supports 5 units including gray, milligray, centigray, microgray, rad. Pick a conversion below for a dedicated calculator, formula, and reference table. For example, 1 Gy = 1000 mGy.
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About these units
Gray (Gy)
- Definition
- The gray (Gy) is the SI unit of absorbed radiation dose, equal to one joule of energy deposited per kilogram of matter.
- History
- Named after British radiobiologist Louis Harold Gray and adopted by the CGPM in 1975, replacing the older rad.
- Current use
- Grays describe doses in radiation therapy, nuclear accidents, and radiobiology research.
Milligray (mGy)
- Definition
- A milligray (mGy) is one thousandth of a gray.
- History
- A metric sub-multiple of the gray used for lower diagnostic doses.
- Current use
- CT scans typically deliver organ doses of 10–30 mGy; milligray is standard in diagnostic radiology.
Centigray (cGy)
- Definition
- A centigray (cGy) is one hundredth of a gray, numerically equal to one rad.
- History
- It was introduced to provide continuity with the older rad unit.
- Current use
- Radiation oncologists commonly prescribe doses in cGy because it matches the familiar rad scale.
Microgray (µGy)
- Definition
- A microgray (µGy) is one millionth of a gray.
- History
- A metric sub-multiple for very low dose measurements.
- Current use
- Background radiation levels and some occupational dose monitoring use microgray.
Rad (rad)
- Definition
- The rad (radiation absorbed dose) is a non-SI unit of absorbed dose equal to 0.01 gray or 100 ergs per gram.
- History
- Introduced in 1953 by the International Commission on Radiation Units and Measurements; largely superseded by the gray since 1985.
- Current use
- Still encountered in US medical and nuclear-industry documentation alongside cGy; 100 rad = 1 Gy.
Frequently asked questions
What radiation (absorbed dose) units can I convert?
This radiation (absorbed dose) converter supports 5 units: gray, milligray, centigray, microgray, rad. Select any pair below to open a dedicated converter with a formula and conversion table.
How accurate is the radiation (absorbed dose) converter?
Conversions use exact definitional factors, so results are accurate to the precision you need for science, engineering, and everyday use. Values are rounded only for display.
Is the radiation (absorbed dose) converter free?
Yes. Every radiation (absorbed dose) conversion is completely free, needs no sign-up, and runs entirely in your browser — your inputs never leave your device.
Free, private, and instant — every conversion runs in your browser.
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