This work presents an updated overview of numerical methods including acoustic viscous and thermal losses. Numerical modelling of viscothermal losses has gradually become more important due to the general trend of making acoustic devices smaller. Not including viscothermal acoustic losses in such numerical computations will therefore lead to inaccurate or even wrong results. Both, Finite Element Method (FEM) and Boundary Element Method (BEM), formulations are available that incorporate these loss mechanisms. Including viscothermal losses in FEM computations can be computationally very demanding, due to the meshing of very thin boundary layers and the added degrees of freedom. These implications can be avoided using the BEM with losses, but other shortcomings affect this formulation as well. Through a simple academic test case, well established acoustic implementations and a newly proposed coupled FEM and BEM method including viscothermal dissipation are compared and investigated.