The cell adequacy is one of the important factor is Pap smear test as per Bethesda reporting system. The adequate number of cells in a given sample helps to effectively check for abnormality of cells. The Pap smear sample with inadequate number of cells will be rejected and patient will be called for collecting sample once again. The cell adequacy is the number of squamous epithelial cells present in the given Pap smear sample. This paper presents an automated method which estimates the number of cells in a given Pap smear image. This method estimates a cell count even when cells are overlapped. The proposed approach first separates disjoint cells and overlapped cell cluster from cervical Pap smear image. Then the overlapped cluster is further segmented to obtain individual cells. The overlapped cluster is selected based on the area factor. That is area of overlapped cluster will be more than disjoint cells. This method uses Bitplane slicing technique for segmentation of overlapped cells. Then the total cell counts is estimated as sum of disjoint cells count and number of cells separated from overlapped cluster. The method is tested on the ThinPrep images publicly available in open access database.