The invention relates to a method of determining a replacement distance when taking aim on a target (2) with a target distance D (6) and an elevation angle α (5) between a line of sight (4) to the target (2) and a horizontal plane (3) with a weapon (9) in order to fire projectiles with an approximately flat trajectory. The replacement distance is determined from the target distance D (6) by means of a correction function, and the correction function is determined exclusively from non-ballistic characteristic values and at least as a function of the target distance D (6) and the difference in angle between the elevation angle α (5) and the shooting angle.