Now resident at Oakwoods Village in Richmond, near Nelson, he celebrates his 100th birthday tomorrow and is as interested in the issues of local body politics as he was when he campaigned for rates reform in Dunedin in the early 1950s.
"If it affects people, you become concerned," he said this week. "And councils affect places in which people live. If wrong decisions are made, it can make life unpleasant or impossible."
Born in Masterton, Mr Calvert was educated in Nelson and Wellington and moved to Dunedin during the Depression, establishing a dental technician's laboratory in Stafford St.
He became involved with the Kew Ratepayers and Householders Association in the 1940s, but it was as organiser of the Dunedin Combined Ratepayers Association's 1953 campaign for unimproved value rating that he first enjoyed local body success.
"Winning against council - I was very pleased with that. It was my first stride out into independence."
His council career comprised a hat trick of by-election wins in 1958, 1961 and 1970 and a spell in the mayoralty from 1965-68, always on a platform of Labour Party principles if not always on the party's ticket. He also had four terms on the Town and Country Planning Appeal Board and was chairman of the Clutha Valley Development Commission in the early 1970s.
During his time as mayor, Mr Calvert officially opened the new learner's pool at Moana Pool and led the council which authorised the introduction of fluoride into the city water supply.
The visit of the Queen Mother in April 1966 stands out as a highlight of his mayoralty, although he did not find anything exalting or terrifying about it.
"She was a dear old soul. She had a good sense of humour and was fairly open. It's a great privilege to be able to get into conversation with a person of that stature. But it's not what makes the clock turn around. There were more important things in the world."
Such as?
"What's facing us now in this area and that - the rating system placing burdens on people," he said.
After his first wife, Eileen, died in 1977, Mr Calvert spent three years at the couple's holiday home in Arrowtown as unofficial and unpaid assistant greenkeeper at the local golf club. He and second wife Win moved to Christchurch and then to Nelson to be near her family.
Mr Calvert has many good memories of the city.
"We had lovely friends living near us, and I had a good little business and clients were loyal to me."
Asked if he had been following the Otago Stadium issue, he said he had not. And anyway, he said, "if you can't do anything about it, it's a pointless effort".
He still enjoys good health, but there is a serious note to that "horror" of retirement - he cannot do the things he used to and takes it hard.
"My hobbies were mostly outdoors and physical, and you get to the stage where you're unable to go on doing them . . . But never mind."
Mr Calvert celebrated his birthday early with a party at Oakwoods on Wednesday, and is in Wellington this weekend for a dinner with friends and family tomorrow.