A method is provided for determining the weight of an agricultural bale that compensates for un-level terrain such as hillsides. The method uses an empty baler tare weight and a full baler weight to determine a raw bale weight. The cosine of the slope upon which the baler sits is then calculated based upon the empty baler weight as it sits and the empty baler tare weight. The cosine of the angle of slope and raw bale weight are then used to determine an actual bale weight. Further steps are provided for compensating in the tare weight of the baler for the weight of wrapping material and/or preservative consumed in the formation of each bale.