Enthalpy increments (ΔH) of alkali borosilicate glasses (BSG) with and without uranium oxide were measured by drop calorimetry. The heat capacity (Cp) of these two glasses was computed from a fitted 4-term polynomial a + bT + cT² + d/T. C_p values were found to be 0.80^–1.00 J g^-1 K^-1 and 0.83–1.13 J g^-1 K^-1 at the temperature range of T = 298–723 K for BSG (GM11) and UO₃-loaded BSG (GM12), respectively. The heat capacity of borosilicate glass (BSG) GM11 and BSG-U (GM12) was also measured by DSC method and found to be 0.90–1.32 J g-1 K^-1 and 0.84–1.19 J g^-1 K^-1 at the temperature range T = 320–760 K. The results were discussed based on the experimental findings.