"Can we calculate the effective mass of a compound without doing theoretical stuff." - effective mass of CARRIERS, perhaps, do You mean? If briefly, no. Just to get from experimental data and semi-empirical (not ab-initio) model.
When you write "without doing theoretical stuff" if you mean "using an experimental method", you can use the four-coefficients method : http://aip.scitation.org/doi/10.1063/1.1150224
(this method is also described in several other papers)