how old are bojack horseman characters?
As mentioned by Charlie Rose in season 1 episode 1 (BoJack Horseman; The BoJack Horseman Story, Chapter One), Horsin' Around first aired in 1987 and went on to run for 9 seasons, ending in 1996, 18 years earlier. From this we can tell that BoJack was on Horsin' Around from age 23 until 32.