This paper compares the results of experiment measurements of wave runup and wave forces on a cylinder to those predicted by analytical models. The objective of the study is to devise methods intended as engineering tools to predict these quantities. For this, appropriate formulae are proposed. Results from the approximation were compared to published data and to data measured in experiments conducted by the authors on a large fixed bottom cylinder. The analytical solutions are based on linear and non-linear diffraction theory, the latter being complete to second-order.