The ship was armed with a main battery of four 12 inch /45 Mark 5 guns in two twin gun turrets on the centerline, one forward and aft. The secondary battery consisted of eight /45 guns and twelve /45 guns. The 8-inch guns were mounted in four twin turrets amidships and the 7-inch guns were placed in casemates in the hull. For close-range defense against torpedo boats, she carried twenty /50 guns mounted in casemates along the side of the hull and twelve 3-pounder guns. She also carried four 1-pounder guns. As was standard for capital ships of the period, "New Hampshire" carried four 21 inch (533 mm) torpedo tubes, submerged in her hull on the broadside.