Convert centigray [cGy] to joule/kilogram [J/kg] Online | Free radiation-absorbed-dose Converter

Centigray [cGy]: A Practical Unit in Radiation Therapy

The centigray (cGy) is a unit of absorbed radiation dose equal to 0.01 grays (Gy), or one-hundredth of a gray. It is widely used in clinical settings, especially in radiation therapy, where doses need to be both precise and clinically meaningful. One centigray equals 10 milligrays (mGy), making it a convenient unit for prescribing and documenting treatment doses.

In cancer treatment, therapeutic radiation is typically delivered in fractions, with each session often delivering 180–200 cGy (or 1.8–2.0 Gy) to the target area. Using centigrays allows healthcare professionals to express these fractions in whole numbers, simplifying treatment planning and communication. For example, a full course of radiation therapy might involve a total dose of 6000 cGy over several weeks.

Outside of therapy, the cGy is less commonly used, but it remains important in any context where mid-level radiation doses are applied or studied. Its use bridges the gap between small exposures (measured in mGy or µGy) and large, high-dose applications (measured in Gy), making the centigray a key unit in applied radiation science.

Joule per Kilogram [J/kg]: The Basis of the Gray (Gy)

The joule per kilogram (J/kg) is the SI unit for absorbed radiation dose, directly defining the gray (Gy). It measures the amount of energy—joules—absorbed by each kilogram of a substance (usually tissue or material) when exposed to ionizing radiation.

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  1 gray (Gy) = 1 joule per kilogram (J/kg).

  
  

This unit is fundamental in radiation physics, radiology, and radiation protection because it quantifies how much radiation energy is deposited in matter, which is critical for understanding biological effects, radiation damage, and safety limits.

Since it measures energy absorbed per mass, J/kg is widely used to:

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  Assess radiation doses in medical diagnostics and therapy.

  
  
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  Monitor exposure in nuclear industry and radiation protection.

  
  
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  Conduct research in radiation biology and physics.

  
  

The joule per kilogram is essential for ensuring consistent, standardized measurements of radiation doses across scientific, medical, and industrial fields.