Grant studied law and commerce at Auckland University, graduating with an LLB Bcom in 1977.
He owned and operated a successful computer/calculator business in the Auckland CBD during 1979-1984, practised chartered accountancy during 1984-1987 and practised law in Pukekohe at King Gerrard Partners since 1987, the last eighteen years as a partner.
Grant specialises in Trust Law, estate planing and administration, charitable trust law, property law and conveyancing.
He is married to Shelley and they have three sons and a grandson. They lead a Christian faith based charity called Goforth Kiwi directed to meet the needs of at risk youth in the Pukekohe North area, assisting their families and generally seeking to alleviate poverty in that area.