Finance & Investing

Retirement Corpus Estimator

Translate your target lifestyle into the nest egg you actually need.

The "25× rule" says you need 25 times your annual spending saved to retire safely. That is a starting point, not a finish line. The real number depends on your spending (not your income), your expected Social Security or pension, your investment return, your inflation assumption, and how long you will live. This calculator replaces the cookie-cutter rule with a number tailored to your actual life.

Your retirement picture

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Your retirement corpus target
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Enter your details to see the nest egg you need.

Note: All calculations run in your browser. Nothing is sent to a server, stored, or tracked.

How this calculator works

The math, in plain English

The 25× rule (or 4% safe withdrawal rate) comes from the 1998 Trinity Study, which tested historical market returns against 30-year retirement periods. The finding: withdrawing 4% of an initial portfolio, adjusted for inflation each year, survived 95%+ of historical 30-year windows. But the rule has limits — it assumes 30 years of retirement, a 50/50 stock/bond mix, and U.S. historical returns. Your mileage will vary.

The formula

Corpus needed = (Annual spending − Annual Social Security/pension) ÷ Safe withdrawal rate

If you spend $60,000/year and Social Security covers $24,000, your portfolio must produce $36,000/year. At a 4% withdrawal rate, that requires $900,000. At 3.5% (more conservative for early retirees), it requires $1,028,000.

A worked example
35-year-old, $80,000 saved, $800/month contribution, 30 years to retire at 7% return. Projected at 65: $80k grows to $610k; $800/month contributions grow to $976k. Total: $1.59M. Needed (with $60k spend, $24k SS, 4% SWR): $900k. Surplus: $690k. They are on track.

Why spending matters more than income

Your retirement need is based on what you spend, not what you earn. Two people earning $100k can need vastly different nest eggs: the frugal one spending $50k needs $1.25M; the lifestyle one spending $90k needs $2.25M. Tracking your spending now — honestly — is the single most important input to retirement planning.

Adjusting the withdrawal rate

4% is the standard for 30-year retirements. If you retire early (50+ year horizon), use 3.5% or even 3%. If you retire late (75+, shorter horizon), 5% may be safe. The lower your withdrawal rate, the larger your required corpus — but the safer you are against sequence-of-returns risk (a market crash in your first year of retirement).

FAQ

Common questions

Is the 4% rule still valid in 2026?
It is a starting point, not a guarantee. Recent research suggests 3.5% may be safer given lower expected bond returns and longer retirements. The original Trinity Study assumed 30 years; if you retire at 55, you may need a 40-year horizon. Use 3.5-4% for traditional retirement, 3-3.5% for early retirement.
Should I include my home equity in the corpus?
Generally no, unless you plan to downsize or take a reverse mortgage. Your home is a place to live, not a liquid asset. If you will sell and rent in retirement, include the net proceeds. If you will stay, exclude it — but you can subtract property tax and maintenance from your annual spending.
What about healthcare before Medicare?
If you retire before 65 (Medicare eligibility), budget $12,000-$20,000/year for ACA marketplace premiums and out-of-pocket costs. This is often the single largest expense in early retirement. Add it to your annual spending for the pre-65 years, then reduce it after 65.
How does inflation affect this?
Your spending will rise with inflation, and your withdrawal rate must rise to match. The 4% rule already accounts for this — you withdraw 4% of the initial portfolio, then adjust that dollar amount for inflation each year. Your investments must outpace inflation to keep up.
What if I want to retire early (FIRE)?
Early retirement changes the math significantly. A 45-year retiree needs a 50-year horizon, which lowers the safe withdrawal rate to 3-3.5% and dramatically increases the required corpus. The trade-off: more years of compounding before retirement, but more years of withdrawals after. Use our compound interest calculator alongside this one.
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Disclaimer: This calculator is provided for educational and informational purposes only. It does not constitute financial, tax, legal, medical, or professional advice. Results depend on the accuracy of the inputs you provide and the assumptions documented above. Always consult a qualified professional before making decisions based on these calculations.