Convert centigray [cGy] to joule/centigram [J/cg] 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 Centigram [J/cg]: A Unit of Energy per Mass

The joule per centigram (J/cg) expresses the amount of energy absorbed or delivered per unit mass, specifically joules of energy per centigram (1 centigram = 0.01 grams). This unit represents energy density on a small mass scale.

To relate it to standard radiation dose units: since 1 gray (Gy) equals 1 joule per kilogram (J/kg), and 1 centigram equals 10⁻⁵ kilograms, then

• 
  

  1 J/cg = 1 joule per 0.00001 kg = 100,000 J/kg = 100,000 Gy.

  
  

This means that 1 J/cg corresponds to a very high absorbed radiation dose, much greater than typical doses used in medicine or radiation safety.

J/cg could be useful in very specialized fields where energy deposition is considered over tiny masses, such as microdosimetry, materials science, or radiation effects at microscopic scales.

In general, joule per centigram is a high-precision measure for energy density per small mass, but it’s not commonly used in everyday radiation measurement, where grays or their subunits are preferred.