Shrub encroachment can be described as the increase in density, cover, and biomass of shrubby plants. Over the last decade shrub encroachment is observed over a wide range of different ecosystems globally. However, it is poorly known how this phenomenon changes ecosystem functions and processes. Increases in shrub biomass can lead to lower species richness, and changes in carbon input in the soil. One way to investigate shrub encroachment is to determine biomass. Measuring the biomass directly can be time-consuming and expensive. Therefore, more studies focus on developing allometric equations to determine the biomass. This method is non-destructive and one variable that is easy to measure in the field can be used to determine a variable that is more difficult to assess. This study developed allometric equations for the estimation of aboveground biomass (total biomass, leaf biomass, woody biomass) for three dominant (dwarf-) shrub species commonly found at the study site Kaserstattalm to constitute a contribution to the global effort of shrub biomass prediction. The investigated species are Vaccinium uliginosum, Rhododendron ferrugineum and Calluna vulgaris. Five variables, crown area (CA), mean height (MH), volume (V), mean stem diameter (MD) and number of stems (NoS) were chosen to estimate the different types of biomasses for these three species. With these variables, linear regression models were calculated. For Vaccinium uliginosum, the model using volume (V) was chosen as the best-fitting model for all types of biomasses. The best model to describe the biomass of Rhododendron ferrugineum and Calluna vulgaris was the model based on crown area (CA). When the biomass of these three species will be investigated in similar regions in the future, it is recommended to use the best-fitting models developed in this study.