Estimate concert setlist length.
Setlist runtime is more than the sum of the songs. Every transition adds banter, tuning or an instrument change, and at forty seconds a gap across twenty songs that is over thirteen minutes of stage time. The encore adds its own walk-off pause. Adding the gaps explicitly is what turns a seventy-minute setlist into the ninety-minute show the audience actually experiences.
Music time
Music minutes = (main set songs + encore songs) x average song length
Total runtime
Show length = music minutes + (songs - 1) x gap + encore walk-off break
Extended intros, crowd interaction and solos routinely add thirty seconds to a couple of minutes per song, which is why entering the studio runtime underestimates the show.
No — this covers the headline set only. Support acts and the changeover typically add sixty to ninety minutes before the headliner starts.