Mudd is a volume measuring instrument that has been widely used as a reference measure in the Islamic region for the payment of zakat, fidyah and kaffarah. Many well-known literatures have their own definition of the mudd, but never being discussed technically in term of volume calibration. A mudd has been calibrated by National Metrology Institute of Malaysia (NMIM) to determine its’ volume, as an effort to standardize the volume of mudd at national level. The result shows that the volume of a mudd is 796 mL. Accurate measurement of the mudd volume is vital since the compensation is to be paid to the poor and needy peoples. This research to determine the volume of a mudd is hopefully to strengthen the institution related with the use of the mudd in the future.