Wave run up is important for quantifying risks to infrastructure in the coastal zone. The performance of global wave run up models are assessed by applying them to two significant storms along the South African coastline in 2007 and 2008. The models produced mixed results and therefore the development of a new wave run up model was undertaken. This model uses the distance offshore to a point on the bathymetric profile, located approximately at the cut off depth, as a proxy for the underwater beach profile. This new wave run up model has been calibrated for open coastlines as well as large and small embayments. The new model outperforms most of the current wave run up models and gives a good first order approximation of wave run up on natural beaches.