In this study we describe and calibrate a quantitative index method to estimate leaf biomass and forage availability for browsers at different feeding heights. The method is based on an index relating leaf biomass to a number of leaf contacts with a vertical, three-dimensional (25×25×165 cm) metallic quadrat with a central rod and takes into account the characteristics of leaves (shape, size, and thickness) to define plant categories and then produce general allometric equations per category. We then discuss the use of this biomass index to evaluate the quality of habitats for browsers in terms of food resources.