This paper aims to develop an integrated method to extract elastic–plastic parameters from a single instrumented spherical indentation curve. The expression of unloading work is chosen to be combined with the previous work [P. Jiang, T.H. Zhang et al, J. Mater. Res.24(3), 1045 (2009)]. An extensive numerical study was performed to examine the effectiveness of the method. Refitting Jiang's similarity solution based on the numerical study was also performed to simplify the form of the expression and improve the accuracy of the elastic–plastic parameters extracted. The results show that the error of our solution was less than ±5%. We also examined its sensitivity by assessing levels of artificial error introduced into the testing parameters used in the method. These results show that this method can provide reasonable estimates of the elastic–plastic parameters for most common metals.