Abstract Many issues involving leaf areas (LA) allometry, such as the possibility of adjusting morphometric models based on the leaves of different species and the influence model performance on intraspecific variability, are still unclear. In this work, we described allometric equations for 14 different woody tropical species. This study’s novelty is to show how a generalised allometric equation accurately estimates LAs of different species with similar leaf morphologies [oblong: Ŷ = 0.6356(LW) 1.0260 , and elliptical: Ŷ = 0.6552(LW) 1.0094 ]. Natural variation that occurs in the leaf development does not represent an obstacle to the implementation of generalised models. In general, simple linear models are considered ineffective to describe the full range of leaf variation. Extrapolation of these equations to other woody species of similar leaf morphology can be compared with models developed for oblong and elliptical leaves, based on the principle that in potential models, the variation of the intercept coefficient (β 0 ) tended to 0.5 for leaves more elongated to 0.7 in less elongated leaves. While the angular coefficient (β 1 ) tended to vary from 0.97 for less elongated leaves, up to 1 when the relationship between LA is remarkably close to a rectangle.