How Much Do You Actually Need to Retire?
The honest answer is: it depends on the lifestyle you want, where you live, and how long you live. But the planning math is simpler than it looks. Decide what annual income you'll want in retirement, divide by a sustainable withdrawal rate, and you have your nest-egg target. Everything else is just figuring out how to get there.
The income replacement rule
A common rule of thumb is that retirees need 70–85% of their pre-retirement income to maintain their lifestyle. The drop comes from no longer paying payroll taxes, no longer commuting, and no longer saving for retirement itself. Higher earners often land closer to 70%; lower earners and those with mortgages still outstanding may need closer to 90%.
The 4% rule
The 4% rule, born from the 1994 Trinity Study, says that withdrawing 4% of your portfolio in year one and adjusting that dollar amount for inflation each subsequent year has historically had a very high probability of lasting 30 years. So if you want $60,000/year in retirement income, you need a $1.5M nest egg ($60,000 ÷ 0.04). Critics argue early retirees with 40+ year horizons should use 3.3–3.5% to be safe.
Why time matters more than the amount
Compound returns reward early savers in a way that feels almost unfair. A 25-year-old saving $300/month at 7% real returns reaches $1M by 65. A 35-year-old has to save nearly $700/month, more than double, to hit the same target. If you have time, use it. If you don't, increase your savings rate aggressively and use catch-up contributions starting at 50.
Account order matters
Always capture the full employer 401(k) match first, it's an instant 50–100% return that no investment can beat. Then knock out high-interest debt. Then a Roth IRA if you qualify, for tax-free growth. Then back to the 401(k) up to the annual contribution limit. An HSA, if you're on a high-deductible health plan, is the best account in the tax code: deductible going in, tax-free growth, tax-free out for medical expenses.
Don't model 10% returns
Yes, the S&P 500 has averaged ~10% nominal historically. But inflation eats ~3% of that, sequence-of-returns risk eats more, and you'll likely shift toward bonds as you age. Plan on 6–7% real and you'll either retire on schedule or pleasantly early. Plan on 10% and you'll undersave by half.