Retirement is not an age — it's a financial number. Learn how to calculate your FI number, optimize 401(k)s, IRAs, and Roth strategies, and plan for healthcare so the math actually works.

FI Number

Retirement Accounts

Social Security

Healthcare Planning

Retirement is a number, not an age

Retirement Planning Guide

Stop planning for an age. Plan for a number — the assets that, deployed correctly, replace your income forever. Once you have the number, the path becomes math instead of vibes.

See the Math Back to Financial Literacy

The 60-Second Answer

How do you calculate your financial independence number?

Take your expected annual spending in retirement, multiply by 25. That's your FI number — the asset base that, withdrawn at roughly 4% per year, has historically lasted 30+ years across most market scenarios. Spending $60K/year? Target $1.5M. Spending $100K/year? Target $2.5M. The wealthy don't aim for a retirement age — they aim for the number, contribute aggressively into tax-advantaged accounts, and stop working when the math says it's safe.

Why This Matters

Retiring at 65 Was Never the Goal

"Retirement at 65" is a 20th-century industrial artifact. The right question is not when can I stop working — it's how much do I need so working becomes optional. Answer that, and your timeline becomes flexible: some people hit it at 45, some at 55, some at 70. The number is the goal; the date is the consequence.

This reframe matters because it puts you in charge of the variable that actually moves the date — your savings rate. Saving 10% of income takes ~50 working years to fund retirement. Saving 25% takes ~30 years. Saving 50% takes ~17 years. The math is absurdly leveraged on this single dial.

Pick the number. Pick the savings rate. The age picks itself.

The Four Levers

The Four Pillars of Retirement Planning

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1. Your FI Number

Annual retirement spending × 25 = target asset base. The 4% rule (Trinity Study) shows this base has historically supported 30+ year retirements. For very early retirements, use 28× (3.5%) to add safety margin.

Quick math: $60K spend → $1.5M FI; $80K → $2M; $120K → $3M; $200K → $5M.

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2. Account Optimization

Order matters more than people realize. Standard order: employer match → high-interest debt → HSA → Roth IRA → 401(k) up to limit → taxable brokerage.

Why: matching is 100% return, debt above 7% beats market expected returns, HSA is triple-tax-free, Roth grows tax-free forever, 401(k) defers tax to lower-bracket retirement.

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3. Social Security Strategy

Social Security is income replacement, not a wealth strategy. For most US workers, it covers ~30–40% of pre-retirement income. The big lever: when you claim. Each year delayed past full retirement age (currently 67) increases the benefit ~8%.

Heuristic: if you can afford to wait, delaying to 70 produces the highest lifetime benefit for those who live past their late 70s.

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4. Healthcare Planning

Healthcare is the most under-budgeted retirement category. Medicare starts at 65 — early retirees need a private bridge. Long-term care insurance is a real consideration past age 60. HSAs are the most tax-efficient way to fund medical costs in retirement.

Estimate: a healthy 65-year-old couple now needs ~$315K saved for medical costs over retirement. Plan for it as a real line item.

Worked Example

Reaching $2M in 25 Years on a $90K Salary

Age 35, target $2M FI by 60. Single income, $90K gross, ~$72K take-home.

• Target spend in retirement: $80K/year. FI number = $2M.

• 401(k): $1,200/month + $400 employer match = $1,600/month → $19,200/year.

• Roth IRA: $7,000/year (current limit).

• HSA: $3,850/year (single coverage), invested not spent.

• Total annual contribution: $30,050. Savings rate ~33% of gross.

• Assumed return: 7% real.

• Projected age 60 value: ~$2.05M. FI hit at 60 with margin.

Median income, no inheritance, no business exit. Just consistent contributions across the right account stack for 25 years. The math is unsentimental — and it works.

Avoid These

Common Retirement Mistakes

• Skipping the employer match — leaving free money on the table

• Cashing out 401(k)s when changing jobs

• Ignoring the HSA — most under-used retirement account

• All-Roth or all-Traditional — usually a mix is better

• Forgetting healthcare costs in the FI number

• Counting Social Security as the whole plan

• Investing retirement money too conservatively in your 30s and 40s

• Investing retirement money too aggressively in your 60s

Frequently Asked Questions

Is the 4% rule still valid in 2026? With reasonable assumptions, yes. The 4% rule has held up across multiple updates of the Trinity Study and Bengen's research. For very early retirees (40s) with 50+ year horizons, 3.25–3.5% is a more conservative starting withdrawal rate.

Should I prioritize Roth or Traditional 401(k)? Mostly depends on your current vs expected retirement tax bracket. Traditional makes sense in high-income years (defer tax now); Roth makes sense in lower-income years and for tax diversification in retirement. Many people benefit from a mix.

What's an HSA and why is it the most powerful retirement account? A Health Savings Account (paired with a high-deductible health plan) is triple-tax-advantaged: deductible going in, tax-free growth, tax-free withdrawals for qualified medical expenses (and after 65, ordinary income for anything). No other US account combines all three.

What if I started saving for retirement late? Three levers: aggressive savings rate (30–50%), longer working horizon, and reduced retirement spending target (which lowers the FI number directly). Late starters need to play all three. There's no single button that fixes a 20-year delay, but the combination still works.

Can I retire on Social Security alone? For most people, no — it covers about 30–40% of pre-retirement income. Could be enough for very low-cost-of-living retirees, but most need substantial savings on top. Treat Social Security as a partial floor, not the plan.

How does FIRE (Financial Independence, Retire Early) differ from regular retirement planning? Same math, more aggressive savings rate, often a stricter spending target. Traditional plan: 15–25% savings, retire ~65. FIRE: 40–70% savings, retire 35–50. The principles are identical; the lever pulled harder is savings rate.

What about the role of bonds in a retirement portfolio? Increase as you near and enter retirement. Common rule: bond percentage = age − 20 (or − 30 for more aggressive investors). At age 30, 0–10% bonds is fine. At 65, 30–50% bonds smooths the ride and protects against sequence-of-returns risk in early retirement.

Retirement Planning Guide: How to Calculate Your Financial Independence Number

Financial Freedom Blueprints