How much money do you need to retire? Ask five financial advisors and you will get five different charts. But there is one single-number shortcut that frames the problem well enough to build a real plan around: you can retire when your savings equal 25 times your annual expenses. $50,000/year of spending? You need $1.25 million. $80,000/year? You need $2 million. $120,000/year? You need $3 million.
That “25x” comes from the 4% rule, and understanding where the rule comes from tells you when to trust it and when to adjust.
The 4% rule: origin story
In 1994, financial planner Bill Bengen analyzed every rolling 30-year period in US market history and asked: what is the highest initial withdrawal rate that survived every period — including the worst starting years like 1929 and 1966? His answer was 4%. Take 4% of your portfolio in year one, then adjust that dollar amount upward for inflation every year after, and you would have made it 30 years without running out of money, even in the worst-case historical scenarios.
The Trinity Study in 1998 confirmed and refined the number. A subsequent generation of research has suggested 4% is modestly optimistic for a 40-year retirement (because there are fewer 40-year windows in the historical record) and roughly right for 30 years. For typical 60-65 retirees, 4% remains the usable benchmark.
Flip 4% into a multiplier: if you need $X per year and can withdraw 4% of your portfolio safely, then your portfolio needs to be X ÷ 0.04 = 25X. That is where the 25 comes from.
Step 1: figure out your retirement spending
Not your salary. Not your pre-retirement income. Your annual spending in retirement. These differ because:
- You stop payroll taxes (7.65% FICA gone — saved)
- You stop saving for retirement itself (that category disappears)
- You probably have no mortgage by then (or should plan to)
- Work expenses — commuting, business wardrobe, lunches — disappear
- Healthcare often increases (more on this below)
- Travel and leisure often increase (especially first 10 years)
Most retirees spend 70-85% of pre-retirement income. A household earning $100,000 and spending $80,000 in working years will often spend about $65,000-$70,000 in retirement — sometimes less, sometimes more depending on lifestyle. Knowing your current spending is the starting point. If you do not know, track it for three months before building any retirement plan.
Step 2: subtract Social Security and pensions
Your 25x target is on self-funded spending. Social Security and pensions cover part of the bill, so subtract them.
Example: You want $65,000/year. Social Security (both spouses) will pay about $40,000. Pension? None. Self-funded need: $25,000/year. Target portfolio: 25 × $25,000 = $625,000.
This is much less intimidating than “$1.6 million”, which is what a naive 25x of $65,000 implies. Social Security is the invisible pension most Americans forget to count — and for lower-and-middle earners, it replaces 30-50% of pre-retirement income by design.
Ballpark Social Security math: your monthly benefit at full retirement age is roughly 40% of your career-average inflation-adjusted earnings, up to a cap. A typical middle-income career produces $2,000-$3,000/month per earner. A dual-earner couple often gets $40,000-$55,000 combined. Check ssa.gov for your personalized estimate.
Step 3: add a safety margin
The 4% rule assumed a 50/50 or 60/40 stock/bond portfolio and the US market’s historical returns. Adjust when:
- Retiring young (before 60): drop to 3.5% withdrawal rate (multiplier 28-30x) because you need a longer horizon.
- Retiring very young (before 50): drop to 3.25% (31x) or plan to earn some money part-time for a few years — the “barista FIRE” approach.
- Heavy on bonds (conservative allocation): drop to 3.5-3.8% because lower expected returns.
- Concerned about future returns being lower than history: drop to 3.5% — this is the “sequence of returns risk” adjustment.
- Willing to cut spending if the market drops: stay at 4% or even 4.5%. Flexibility is a safety valve the rigid rule ignores.
Healthcare: the retirement x-factor
If you retire before 65 (Medicare age), you need health insurance. Unless you are covered by a working spouse or a retiree plan, ACA marketplace insurance runs $600-1,800/month per person depending on subsidies, age, and state. That is $7,000-22,000 per year per person, on top of deductibles and out-of-pocket costs. This is the single biggest threat to early retirement budgets.
Post-65 Medicare covers most medical costs, but not all. Medicare Part B premiums, Medigap or Advantage plans, Part D (drugs), dental, vision, and hearing together typically run $300-700 per month per person. Long-term care is a separate, larger risk — a nursing home averages $90,000-$120,000/year and is not covered by Medicare.
Budget at least $15,000/year for healthcare in retirement (couple, post-65) and significantly more if retiring earlier.
An example with real numbers
Couple, both 35, earn combined $140,000, currently save $20,000/year in retirement accounts ($300,000 current balance).
Target retirement spending: 80% of current = $80,000/year in today’s dollars.
Expected SS at 67 (both): $45,000/year combined.
Self-funded need: $35,000/year.
Target portfolio at 67: 25 × $35,000 = $875,000 in today’s dollars.
With $300,000 today, compounding at 6% real (after inflation) for 32 years, the existing balance grows to $1.94 million in today’s dollars. Even if they stopped contributing entirely, they would overshoot the target. Add their annual $20,000 contributions and they end up around $3.5 million — well beyond the minimum.
This is the comforting insight for many mid-career savers: if you started reasonably early and are contributing consistently, the 25x target may already be within reach. Run your numbers before assuming the worst.
When the rule breaks
Do not blindly apply 4%/25x if:
- You plan to buy a house or make a large one-off purchase in retirement (that is not a “yearly expense”)
- You have major medical expenses coming (lump-sum adjustments needed)
- You want to leave money to heirs or charity (then 3% is more appropriate)
- You expect decades of low returns (the “lost decade” scenario requires dialing down)
- Your living expenses are highly variable year to year
Project your path
Our retirement calculator takes your current age, current savings, annual contributions, expected return, and target retirement age, and returns a projected balance. You can compare what you will have at 65 versus your 25x target and see the gap in real dollars. Adjust your contribution rate until the two numbers meet. That is the conversation — and the action — that turns an abstract retirement goal into a concrete plan.