There is in the literature a lot of determinant formulae involving the rela
tive class number of an imaginary abelian field. Usually such a formula con
tains a factor which is equal to zero for many fields and so it gives no in
formation about the class number of these fields. The aim of this paper is
to show a way of obtaining most of these formulae in a unique fashion, name
ly by means of the Stickelberger ideal. Moreover some new and non-vanishing
formulae are derived by a modification of Ramachandra's construction of in
dependent cyclotomic units.