The compressive strength of concrete, although, conventionally, used to be determined either by destructive tests of cubes cast in-situ, or from concrete cores extracted from an existing structure, can be easily estimated at present with the help of empirical correlations with inputs from non-destructive test results of Rebound Hammer and Ultrasonic Pulse Velocity. The main contribution of this paper lies in the proposition of empirical correlations for compressive strength determination from a global uncertainty perspective, not considered previously to the best of the authors’ knowledge. To fulfil this objective, correlation equations published worldwide for both univariate and bivariate relationships have been collected and the most suitable ones selected based on their statistical reliability. Further, linear and non-linear regression analysis have been performed on justifiably chosen datasets for the predictor variables. Finally, Linear, Polynomial, Power and Exponential models are developed with appreciable metrics outcomes for all three types of correlations and the best three models proposed after successful validation on country-wise in-situ data accumulated from various literatures.