In this paper, we study the thermodynamics of black holes using a generalized uncertainty principle (GUP) with a correction term linear order in the momentum uncertainty. The mass-temperature relation and heat capacity are calculated from which critical and remnant masses are obtained. The results are exact and are found to be identical. The entropy expression gives the famous area theorem upto leading order corrections from GUP. In particular, the linear order term in GUP leads to a √ A correction to the area theorem. Finally, the area theorem can be expressed in terms of a new variable termed as reduced horizon area only when the calculation is done to the next higher order correction from GUP.The idea of existence of a minimal length arises naturally in quantum gravity theories in the form of effective minimal uncertainty in position. For example, in string theory, it is impossible to improve the spatial resolution below the characteristic length of the string which is expected to be close or equal to Planck length. Based on these arguments, the conventional Heisenberg uncertainty principle has been modified to the generalized uncertainty principle (GUP) [3], [4]. This idea, proposed first in [5], has led recently to a considerable amount of study in various areas of physics. For instance, the laws of black hole thermodynamics [6]- [8] has been investigated under this modification [9]-[12], quantum gravity corrections are computed in quantum systems (such as particle in a box, Landau levels and simple harmonic oscillator) [13]-[17], Planck scale corrections are obtained in the phenomena of superconductivity and quantum Hall effect [18] and its implications has been studied in cosmology [19], [20].In this paper, we will find the thermodynamic properties of the Schwarzschild and Reissner-Nordström (RN) black holes using the following form of the GUP proposed in *