Absorption and scattering coefficients are, together with quantum efficiency and spectral response, fundamental parameters that describe fluorescent phosphors and their behavior in white LEDs, fluorescent lamps and displays. Simple reflectance measurements typically performed in industry often confound the absorption and scattering coefficients and understanding their individual contributions can be challenging. In this talk we will describe techniques that allow, in a simple and precise manner, to measure accurately and independently the absorption and scattering coefficients relative to a reference sample.