Leaf area is related to tree growth, water balance and mechanical resistance to physical and biotic agents. Currently there are no studies of its estimation focused on studying its importance in forest species in Peru. Hence, the purpose of the present study was to compare two non-destructive methods of leaf area estimation: ImageJ free software vs. a manual method using graph paper, in seedlings of the Peruvian endemic species “Quina”. Three young leaves and three mature leaves were evaluated on 18 seedlings of Cinchona, for a total of 108 data points. The leaves were identified, coded and placed on an A4 sheet of paper with a millimetric scale, photographed at 30 cm perpendicularly and evaluated using ImageJ software. In the same way, the measurement was carried out on sheets of graph paper, delimiting the leaf lamina and calculating the dimensions considered. Descriptive statistics were obtained for both methods. They were compared using the non-parametric Kruskall Wallis test, and a simple linear and quadratic regression equation were estimated based on the parameters of width and length. We obtained a greater adjustment in the quadratic one.