Evapotranspiration is an important component of the hydrologic cycle and plays a significant role in determining the crop water requirement. Evapotranspiration from a cropped surface is influenced by a number of factors which may be broadly classified as crop related factors and meteorological factors. FAO-56 Penman Monteith method is universally accepted as the standard method for calculating reference evapotranspiration. However, the meteorological inputs for this method are difficult to obtain. In this context, the user is forced to rely on simple temperature and radiation based empirical equations which require lesser number of inputs which are readily available. Here, an attempt is made to statistically compare five different empirical reference evapotranspiration estimation methods, with Penman Monteith method as reference, in six different climate types prevailing in Karnataka. The calculations are done on daily and monthly time scales using computer programs developed in Microsoft Excel.