Most suspension designers are familiar with both the concept of the roll centre and with suspension jacking in independent suspensions. The connection between them is less widely appreciated. This paper analyses the mechanisms of jacking, using the roll centre concept as a departure point. In doing so, a set of hand calculations, intended as a toolkit for the designer, is developed. Practical applications of the theory are discussed, such as ‘zero jacking’ suspensions and gradient traverse performance of off-road vehicles.