The arithmetic
The target comes from the four percent rule, drawn from studies of historical American market returns. A retiree who withdrew four percent of a balanced portfolio in the first year, and adjusted that dollar amount for inflation afterward, would not have run out of money over any thirty-year period in the record. Invert four percent and you get twenty-five. Spending of $40,000 a year needs $1 million, and spending of $80,000 needs $2 million. The rule describes the past, guarantees nothing, and was built for thirty-year retirements. Someone stopping at forty may need the money to last fifty years, so many early retirees plan on 3.25 to 3.5 percent, which means roughly twenty-nine to thirty-one times expenses.
Savings rate sets the clock
Time to independence depends mainly on the share of take-home pay you save, because a higher rate both builds the pile faster and shrinks the pile you need. Assuming a five percent return after inflation, saving ten percent of your income takes about fifty years from zero, twenty-five percent takes about thirty-two, and fifty percent takes about seventeen. Those figures are illustrations and not forecasts. The large levers are housing, transportation and food, which make up most household spending.
The practical obstacles
- Health insurance comes first, because Medicare starts at sixty-five and until then you buy your own coverage, generally through the marketplace.
- Access comes second, because retirement accounts generally carry a ten percent penalty on withdrawals before fifty-nine and a half. The usual bridges are a taxable brokerage account, Roth IRA contributions, which can come out at any time, and Roth conversions, which become available after five years. Each has traps, so review them with a tax professional.
- Social Security comes third, because the benefit is computed from your highest thirty-five years of earnings, and a short career puts zeros in the average.
- Sequence risk comes fourth, because a crash in the first five years of withdrawals does far more harm than a later one. The defense is flexibility, which means trimming spending or earning a little in bad years.
Versions short of quitting
Many people who chase the number never stop working. They move to part-time work, to a lower-paying job they prefer, or to a position from which they can say no. It is worth knowing what you are retiring to, since unstructured years suit fewer people than expect them to.
Note Track your actual spending for one full year before doing any of this math. Most people guess low, and every figure above rests on that one number.
