Double coverings with h2,0=0 over compact Kähler manifolds

We give a formula for Hodge numbers of double coverings with h2,0=0 over compact Kähler manifolds. As an application, we consider Calabi-Yau double coverings and calculate their Hodge numbers. In this way, we find several pairs (h1,1,h1,2) of Hodge numbers of Calabi-Yau threefolds that do not come from toric setting.