The mathematical concept that used to measure the complexity of the fractal sets is known as fractal dimension. It is considered as a global feature for fractal images. Many methods have been proposed to estimate this value according to object nature. Differential Box Counting method is one of the most important methods used to estimate the dimension of gray scale image. In this paper, we proposed a new method based on the aggregate gray level values in the image. The results of the experiments show an improvement over the traditional DBC method.