Abstract Calibration of an earth‐plate forage capacitance meter was conducted on pure stands of Festuca arundinacea Schreb., Medicago sativa L., Cynodon dactylon (L.) Pers. and Trifolium repens L. and a mixture of Trifolium repens and Dactylis glomerata L. Dry weight (DW) prediction equations were developed using the instrument capacitance reading modified by visual estimates of height, stand density and species percentage. In general, meter readings (MR) correlated better with DW than with fresh weight or weight of water and especially when the area harvested exceeded 0·537 m 2 . Correlation between MR and DW improved with increasing top plate area and with decreasing distance between the top plate (suspended sheet of aluminium) and the earth‐plate ground. The use of a plastic shield to suppress the forage to a uniform height caused a reduction in the correlation between MR and DW. The use of MR to predict DW from selected settings, their linear and curvilinear relationships and several auxiliary observations gave results with R 2 values ranging from 0·94 to 0·99, depending on species and mixture.