Current vs. retirement income: How much do I need?:
some people say you need 70 percent of pre-retirement income after retiring, while others claim it’s 80 percent, 85 percent or 90 percent. But whatever version of this rule you hear, I think you need to take it with a very large block of salt. Of course, that’s true of all rules of thumb, whether it’s the percentage of pre-retirement income you need, “the 4 percent rule” on withdrawing funds from your portfolio in retirement, the “save 10 percent for retirement rule” or any other benchmark.
After all, rules of thumb are shortcuts; they’re solutions that are supposed to work for the “average” person.
Good advice. The rules of thumb can help you get an idea of the ballpark for a fictional “average” person in general. But your particular situation is different.