B&M wants to expand from 686 shops in the UK to 950.
The discount retailer, which also has 275 Heron Foods stores in the north of England and 104 Babou stores in France, confirmed the expansion plans in an upbeat market update.
B&M unveiled a 2.4% increase in pretax profit to £241.4m during the six months to 25 September, while adjusted pretax profit fell by 6.2% to £238m. It increased its interim dividend by 16.3% to 5p per share.