AbstractCrown cover can be used to describe or classify woody vegetation. However, current methods for the estimation of crown cover are difficult to apply and are time‐consuming. The objective of this work was to present a much easier method of field estimation and to define the limitations of the method.The method uses the crown‐gap ratio (C), which is defined as the mean gap between crowns divided by the mean crown diameter. The relationship between values for the crown‐gap ratio and crown cover is of the form crown cover = k/(1 + C)2, where k is a constant.The overall tasks are first, to develop a methodology to obtain estimates of C and crown openness in the field, and second, to estimate k.In Part 1 we demonstrate that crown cover can be related to C when applied to woody vegetation. In Part 2 we consider a derivation of C, determine a value for k given a set of constraints, and outline some of the sampling implications of applying the method of crown cover estimation using C and k to field situations.The field study provided data from which to plot crown cover against the crown‐gap ratio (C). The shape of the curve approximated a rectangular hyperbola. The regression of crown cover against 1/(1 + C)2showed a strong linear relationship (R2= 0.995) and gave an estimate for k of 0.79 for the range of plant communities sampled.The field study suggests that to investigate the effect of different spatial distributions of crowns and mixtures of crown sizes on C, a rigorous derivation of the relationship between crown cover and C is r