Standard Reference Method (SRM) is the method established by the American Society of Brewing Chemists (ASBC) for assessing the color of wort or beer.
Color Units EBC (European Brewery Convention) is the method established by the European Brewery Convention for assessing the color of wort or beer.
Both methods involve measuring a beer sample color in a cuvette that is placed in a spectrophotometer at a wavelength of 430 nm. However, SRM color is measured using a 1/2 inch cuvette whereas EBC color is measured using a 1 centimeter cuvette. The result is that EBC color is approximately 1.97 times the SRM color.
The equations for converting SRM to EBC or vice versa are fairly simple:
SRM = EBC x 0.508 EBC = SRM x 1.97
Therefore, let's say that on an exam (cough, cough) you are asked to convert a beer's color of 16 SRM to EBC, all you have to do is multiply the SRM by 1.97 to figure out the EBC:
EBC = 16 x 1.97 = 31.52