He was the son of William and Louisa Katharine How (née Ardil).
On 24 July 1907 he married Helen Rose Huth (1837-1924). He was her second husband, the first being Louis Huth (1821-1905). Arrangement in Black, No. 2: Portrait of Mrs Louis Huth y125 stayed in the possession of her first husband's family after his death.
How was a classical scholar, a lecturer (1884) and Fellow (1886-1919) at Exeter College, Cambridge. He was Bursar of the college from 1892-1919, and became an Honorary Fellow on his retirement in 1919.
'Mr. A. B. How', The Times, London, 3 March 1947, p. 6. Young, Andrew McLaren, Margaret F. MacDonald, Robin Spencer, and Hamish Miles, The Paintings of James McNeill Whistler, New Haven and London, 1980 .