Few days ago I got sample of toroidal core from my friend. I don't know any technical details of core just know OD-10cm, ID-6cm, height- 5cm and wet about 1.845 kg(M4 grade,Flux- 1.5T). I want to make toroidal transformer using this core but how to calculate core area and maximum VA capacity of core if Main voltage is 230VAC/50Hz. Attach Test certificate of Core manufacturer.