Convert kilogray [kGy] to rad [rd] Online | Free radiation-absorbed-dose Converter

Kilogray [kGy]: An Ultra-High Dose of Radiation

The kilogray (kGy) is a unit of absorbed radiation dose equal to 1,000 grays (Gy). This represents an extremely large amount of energy—1,000 joules of ionizing radiation absorbed per kilogram of matter. Such doses are far beyond those encountered in medical or environmental settings and are typically relevant only in specialized industrial and scientific applications.

Kilograys are commonly used in radiation processing, such as:

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  Sterilization of medical supplies and pharmaceuticals, where very high doses ensure the destruction of bacteria, viruses, and other microorganisms.

  
  
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  Food irradiation to increase shelf life and reduce pathogens.

  
  
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  Material modification, including polymer cross-linking and degradation studies.

  
  
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  Radiation hardness testing for electronics and materials exposed to extreme environments, like space or nuclear reactors.

  
  

In biology and medicine, doses in the kilogray range would be lethal to all known life forms. Therefore, the kGy is never used to describe radiation exposure to humans or animals.

The kilogray highlights the versatility of the gray as a unit of radiation dose, scaling from tiny fractions used in diagnostics to massive doses used in industrial processes, reflecting the broad spectrum of radiation’s applications across science and technology.

Rad [rd]: A Legacy Unit of Absorbed Radiation Dose

The rad (short for radiation absorbed dose) is a legacy unit used to measure the amount of ionizing radiation energy absorbed per unit mass of material. It was widely used before the adoption of the gray (Gy) in the International System of Units (SI).

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  1 rad = 0.01 gray (Gy)

  
  
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  This means that 1 rad corresponds to the absorption of 0.01 joules of radiation energy per kilogram of matter.

  
  

The rad was commonly used in medical, industrial, and scientific settings to quantify radiation doses. Although now largely replaced by the gray for consistency and international standardization, the rad is still sometimes referenced in older research, medical records, and certain fields.

The rad and its subunits (like the millirad) helped establish the groundwork for understanding radiation exposure and effects before the transition to the more precise and universally accepted gray unit.