No matter what plane you have, it is easy to locate the CG. All the information you need is on www.rcaeronauts . You can accurately locate the CG and NP for any single- or multi-panel conventional airplane and all of the math is done for you. Calculators typically approximate the CG location for single-panel wings. If you have a multi-panel wing, the accuracy from a calculator, will probably be off.

Caution: It is not the CG location alone, that determines pitch stability, but the location of the CG relative to the neutral point. An accurate way to find both the CG and Neutral Point, is crucial.