Pressure buildup test is one of the main pressure transient analyses that offers so many parameters that help for reservoir optimization, characterization, and material balance calculations.  One of the main objectives of pressure buildup is to determine the average reservoir pressure in the drainage area. Several approaches used to get it. They are Horner, Arps and Smith, MDH, MBH, and Muskat extended methods. This paper compares between all these and investigate the differences and the domain of the applications using several field examples taken from Egyptian fields. After that, a simulation study for these field cases has been performed using Saphir software. Wells drilled in Bayahria formation (Egypt) have been chosen from this study and the recorded tests were analyzed by all methods along with Saphir software. The range of the reservoir pressure is above 2200 psi. The accuracy of each method is calculated. The lowest error method is Arps and smith, Muskat and MBH methods in the first case (the error is less than 1.2%) and MBH and MDH in the second case since the error percentage is less than 4%. Ramey–Cobb method is having the highest error in both cases. The accuracy measurement of reservoir pressure is very beneficial not only in the current reservoir calculation but also for the future calculation and field development plan such as water flowing and enhanced oil recovery. This study represents a road map for using such methods for reservoir pressure calculation for the Egyptian oil fields.