Ploughing with a traditional plough requires bed-like movement of the unit. The field is divided into beds (strips) and each of them is processed individually. Two ways of movements alternate. They are called “ridge” (moving in a clockwise direction) and “furrow” (moving in counter-clockwise direction). At the end of the field units do stretched turns in a strip called “strip for turning”. The width of this strip depends not only on the parameters of the unit but also on the shape of the field. In the article correlations have been produced for determining the width of strip for turning when ploughing with a traditional plough in a field with irregular shape and conditions in which the strip width is minimum have been determined.