After moving to England in 1950, she studied at the Chelsea College of Art. Kinneir, her tutor there, was appointed head of signs for Britain's roads. He then hired Calvert to redesign the road sign system and she came up with simple, easy-to-understand pictograms, most notably the signs for 'men at work' (a man digging), 'farm animals' (a cow), and 'schoolchildren nearby' (a girl leading a boy by the hand, whom she later revealed to be herself), based on pre-existing European road signs.
In addition to her road signs, she has designed commercial fonts for Monotype, including the eponymous 'Calvert' font, which she created for use on the Tyne and Wear Metro system. She was awarded an honorary degree by the University of the Arts London in 2004.
OUT OF THE BLUE ; When 50 Artists Were Asked to Think Ink and Create a Masterpiece Using Only a Ballpoint Pen, Few Could Imagine the Extremes to Which the Doodle Bug Would Take Them. the Results Certainly Leave an Indelible Mark, Says Oliver Bennett
May 23, 2004; The ballpoint pen is an impoverished medium, one might think: usually cheap, often nasty, only used in the absence of something...