He married Rebecca, the daughter of the Rev. John Goodwin, rector of Clapham, Surrey, but had no children. They lived at Hunsdon House, which his widow rebuilt after his death.
^ abBrooke, John (1964). L. Namier; J. Brooke (eds.). "CALVERT, Nicolson (?1724-93), of Hunsdon, Herts". The History of Parliament: the House of Commons 1754-1790. Boydell and Brewer. Retrieved 5 June 2014.