Figuring Out Your Number
The most common starting point people run into is the so-called 4% rule. You take your annual spending in retirement and multiply it by 25. If you spend $60,000 a year, you need $1.5 million. Simple enough on paper. The problem is that most people use their current spending instead of their actual retirement spending, which throws the whole calculation off because expenses shift dramatically once you stop commuting, stop buying work clothes, and hopefully retire from your main career. There are more sophisticated approaches beyond the 25x multiplier. Monte Carlo simulations run thousands of hypothetical market scenarios and give you a probability of success rather than a single number. Some people use the Trinity study framework, others build custom cash flow models. I have a colleague who runs a blended approach where she stress-tests against the worst 10% of historical sequences but also builds in a buffer for healthcare and long-term care scenarios that most standard calculators ignore entirely. One thing beginners consistently mess up is sequence of returns risk. This is the danger of retiring right before a major market downturn. If your portfolio drops 30% in your first year of retirement and you're still withdrawing 4%, you're not just down 30% — you're down significantly more because you sold depreciated assets to fund your living expenses. A market crash in years one through five of retirement does far more damage to your portfolio than the same crash in year fifteen when you've had time to recover. This is why some financial planners recommend a bond ramp strategy where you hold two to three years of expenses in cash or short-term bonds at retirement so you don't have to sell equities during a downturn.
Healthcare is another blind spot. Most rough calculations assume Medicare covers everything after 65. It doesn't. Medicare Parts A and B leave significant gaps. A typical couple retiring at 65 might spend $300,000 to $400,000 on healthcare over their retirement years according to Fidelity's estimates, and that's before long-term care. If someone in your family has a history of late-life health issues, this number can easily double. I had a client who built her entire retirement plan around a $2 million number without factoring in that her father required five years of assisted living. She ended up dipping into her retirement portfolio prematurely and had to revise everything downward by about 40%. Taxes matter more than most people realize. Withdrawal order from different account types — taxable, tax-deferred, and Roth — can change your effective withdrawal rate by a percentage point or two over a thirty-year retirement, which compounds into tens of thousands of dollars. Social Security optimization also plays a role. Delaying benefits past full retirement age increases your annual payment by roughly 8% per year up to age 70. For many people, the decision to claim at 62 versus 70 is the single largest choice that affects their overall number. The hard truth about any calculation you do is that it will be wrong. No model accounts for lifestyle changes, unexpected family obligations, major home repairs, or your own behavior under stress. People tend to spend more in early retirement when they're traveling and active, then more later when healthcare kicks in. The best approach is to treat your number as a directional guide rather than a precise target, run the scenarios, build in a 15-20% buffer, and plan to revisit the calculation every two to three years with actual data rather than assumptions.
