Rothesay was  long overall and  between perpendiculars, with a beam of  and a draught of . The Rothesays were powered by the same Y-100 machinery used by the Whitby class.
Rothesay measured in length overall and had a width between perpendiculars of , with a draft of . This ship was equipped with the identical Y-100 engine system as those found on the Whitby-class vessels.