With increasing fuel prices, airlines are searching for means to reduce fuel consumption. Due to the limited variables that operators can influence of an aircraft, they are left with only operational changes, such as center of gravity positioning. By shifting the center of gravity aft, achieved by loading heavy cargo and baggage in the rear, trim drag will decrease. Despite the relation between the center of gravity and the trim drag, and therefore fuel consumption being known, no literature exists on its quantification in practice. As such, at the request of KLM Loadcontrol, a numerical model was developed to investigate the effect of the center of gravity on fuel burn. Due to the complexity, the results were used to derive a function per aircraft, route and season. Defining the zero fuel weight and the center of gravity location for that condition will enable users to determine the effect.