Liquid gauging system for liquid in a container includes a plurality of sensors; each of the sensors measuring a respective parameter of the liquid in the container and producing a sensor output related to its measured parameter; there being at least two sensors that measure different parameters of the liquid; and a processor that receives the sensor outputs and determines, based on the sensor outputs, a quantity of the liquid in the container; the processor determining the quantity by executing at least one sensor fusion algorithm that is based on a set of relationships between the measured parameters and the quantity. The gauging system can also include a data fusion process for determining quantity based on a plurality of quantity measurements.