The estimation of borrow pit volumes is common in many surveying and highway applications. The trapezoidal method (rectangular or triangular prisms), classical cross sectioning (trapezoidal, Simpson, and average formula). and improved methods (Simpson-based, cubic spline, and cubic Hermite formula) have been presented in the literature. The purpose of this paper is to compare volumes determined by the existing methods with Volumes calculated by rectangular prisms using the gridding method of natural neighbor on example 2 in a paper by Chen and Lin. which was also used in a work by Easa. The multiquadric and minimum curvature gridding methods tested in Yanalak and Baykal are also applied to this example. For these volumes, excavation height values in a 1 m grid are interpolated using gridding methods of natural neighbor, multiquadric. and minimum curvature. Then. excavation volume is determined rectangular prisms. The results are compared with the existing volumes in a paper by Easa.