In 1876, he married Lucy Shipton.
They had three children:
1. Dora Winifred Marion Calder was born on 19 July 1877 at St Peter's Parsonage, Hamilton. Dora died in 1878 at the age of just five months.
2. Basil Ambrose Gillies Calder (1881 - 1964). Basil married Frances Corbett (daughter of Alfred and Louanna "Loucy" Corbett nee Gibbons who had married in 1884) (1885 - 1948) in 1907. Basil and Frances had several children, including:
2.1 Nancy Gillies Calder (4 June 1908 - 1990) married William Walter Carey (25 August 1899 - 1976) in 1929
2.2 Betty Frances Calder (1910 - 1971) married Ian Douglas Syminton (son of James Wilson and Katherine Syminton nee MacKay, who had married in 1904) (20 April 1905 - 1975) in 1930.
3. Jasper Cyril Austen Calder (1885 - 1956) married Agnes Baxter Keane Clarke (1882 - 1853) on 17 April 1912 at Christ Church in Whangarei. Together, they had two sons:
3.1 Denver Harold Calder (4 October 1914, Auckland - 16 February 1984)
3.2 Matthew Lewis Calder (11 February 1918 - 1989) married Joan Katherine Calder in 1943.
Contemporaneously, the following appeared in the New Zealand Cyclopedia:
THE REV. CANON WILLIAM CALDER. Vicar of All Saints', Ponsonby, Auckland, and Bishop's Chaplain, was born at Chesterfield. England, and educated at the grammar school of that town. In 1873, he was appointed warden of the Iolani College, Honolulu, and remained there two years, when he came to Auckland, and was appointed incumbent of St. Peter's, Hamilton, Waikato, where he remained until 1881, when he was elected incumbent of St. George's, Thames. In 1883, he was appointed to All Saint's, Ponsonby, of which he is still vicar. Whilst residing at Hamilton, he was made a Mason in Lodge Beta, I.C., in 1876, and has held the rank of Grand Chaplain to the Provincial Grand Lodge of Scotland. He was a member of the Thames Licensing Committee for two years. Canon Calder has been chairman of the Diocesan Board of Education, and of the Diocesan Choral Association. He is very musical, and his is the only Anglican parish in Auckland that has two choirs. During 1896 Canon Calder visited the Motherland, in consequence of ill-health, and returned the same year, not much benefited by his trip. Since he took charge of All Saints' parish, Canon Calder has been instrumental in establishing athletic and cricketing clubs, and a literary society. He also gives great attention to the Sunday school and general ministerial work, and is affectionately known by his congregation and the general public as “Parson Calder.”
The following entry appeared in an Anglican Dictionary of Clergy: