Born in Omaha, Nebraska, he spent two years in the army during World War II and began his television career as KMTV-Omaha's first newscaster. It was at KMTV that he mentored his most famous protégé, Tom Brokaw.
Having attracted national attention for his coverage of the manhunt for mass-murderers Charles Starkweather and Caril Ann Fugate, in 1962 he became a popular anchorman for WNBQ-TV (later known as WMAQ), NBC's owned-and-operated station in Chicago. The broadcast quickly became Chicago's top-rated news program and remained so until WLS' introduction of the so-called "happy talk" news format in 1968. In the late 1960s, Kalber also began doing five-minute news digests in early and late afternoon timeslots on NBC, during which a national audience became familiar with his work. At various points in the 1970s, he anchored weekend broadcasts of NBC Nightly News. In 1975 WMAQ paired Kalber with the then unknown Jane Pauley, who was recruited from a station in Indianapolis; this arrangement did not succeed. Pauley left a year later to become the news anchor for NBC's Today Show.
Moving to national broadcasting for the NBC television network, Kalber was one of the most visible broadcasters in the country from 1976-1981 while anchoring the news on Today, working with hosts Brokaw and Pauley. He left the program after Brokaw went to NBC Nightly News. Kalber later was recruited again to Chicago broadcasting by station WLS in 1984, where he anchored the popular 6 p.m. evening news broadcast until retirement in 1998.