Zero-fuel weight
The zero-fuel weight (ZFW) of an aircraft is the total weight of the airplane and all its contents, minus the total weight of the usable fuel on board. Unusable fuel is included in ZFW. Remember the takeoff weight components contributions: O E W + P L + F O B = T O W {\displaystyle OEW+PL+FOB=TOW} Where OEW is the Operating Empty Weight (that is a characteristic of the plane), PL is the Payload actually embarked, and FOB the Fuel actually embarked and TOW the actual take-off weight.