An equation used to explain band broadening in chromatography. The equation represents the height equivalent of a theoretical plate and has three terms. The A-term is used to describe eddy diffusion, which allows for the different paths a solute may follow when passing over particles of different sizes. The B-term is for the contribution caused by molecular diffusion or longitudinal diffusion of the solute while passing through the column. The C term is the contribution of mass transfer and allows for the finite rate of transfer of the solute between the stationary phase and mobile phase. h = A + B/v + Cv.