A method which is similar to regression estimation method is the calibration estimator. The calibration estimator uses auxiliary variable(s) information to produce efficient estimates. Calibration requires that we know population totals for one or more auxiliary variable (x variables). The efficiency of the calibration estimator depends on how well the auxiliary variables explain the variability of y, the variable of interest. To improve the quality of estimates in sample surveys some kind of weighting is often carried out. This article reviews the calibration estimator which is one of the weighting method and attempts to show calculation of calibration weights with a hypothetical data.