Peter Ritchie Calder was born on 1 July 1906 in Forfar, Scotland, the youngest of four children of David Lindsay Calder, a linen worker, and Georgina Ritchie, the daughter of a master mason.
Peter Ritchie Calder was born on 1 July 1906 in Forfar, Scotland, being the youngest of four offspring of David Lindsay Calder, a worker in the linen industry, and Georgina Ritchie, the child of a master craftsman who built structures.