I guess that every profession has them – the questions that you are asked in a social setting, that seem quite simple but then rapidly lead to a ‘rabbit hole’ of discussion. For me that question is “how much money do I need to accumulate to retire comfortably?” The question is important, and it fits well with the logic of setting a destination before embarking on any journey. Much like the social setting, in this column I cannot provide specific or personalised advice, however, there are some questions, and a simple formula, that can be applied when trying to answer this question. 1. When do you want to retire? Or, as I now describe retirement, when do you want work to be optional? Some people might choose the current age of entitlement to NZ Super (age 65) but for others it may be earlier or later. This date not only sets the time frame for the accumulation of capital but also helps set the time frame over which funds may be consumed. 2. How long do you think you...