An analysis of the relationship of leaf length (LL) and leaf width (LW) with leaf dry weight (LDW) in Panicum maximum was carried out with the objective of improving estimations of tissue flow in that plant. Data was collected in a mob grazing experiment with 28 days grazing interval sampled the day before grazing in 9 grazing cycles. Regression analysis revealed highly significant effect (P \u3c 0.001) of both LL and LW on LDW. A lack of fit test gave strong evidence of non-linear relationship of LDW with LL (p \u3c 0.05), fitting the model 1 0 LDW = β0LLβ1 , while LW presented a linear relation with LDW. LL was a better predictor of LDW than LW. LL solely or in combination with LW produced equations with high R2 (0.61 – 0.90 and 0.80 – 0.92, respectively). The power relationship between leaf length and leaf dry weight imply that longer leaves are heavier per unit of length and, therefore the use of a constant to describe dry weight may be misleading when treatments affect leaf size in Panicum maximum pastures