At what ratio will potassium and sulfur form a binary ionic compound?

Since potassium is a metal with an ionic charge of 1 + and sulfur is a nonmetal with an ionic charge of 2-, we can write their ratio this way,

K^1 + = 1

S^2 - = 2

and then exchange their values in which we call the crossover method and then check if they are in their simplified form.

The final or end result would be K2S, note that the two is a subscript of K.