How Much Do You Need to Retire? A Complete Guide to Your Number

Figuring out how much money you need to retire is one of the most important financial questions you will ever face. The answer is different for everyone, but the methods for finding it are well-established and grounded in decades of research. This guide walks you through the frameworks, variables, and strategies you need to calculate a retirement number that actually works for your situation.

The 4% Rule: The Starting Point

The 4% rule is the most widely known guideline for retirement planning. Introduced by financial planner William Bengen in 1994, it states that you can withdraw 4% of your retirement portfolio in the first year, then adjust that withdrawal amount for inflation each subsequent year, and have a high probability of not running out of money over a 30-year retirement.

The rule is based on historical market data showing that a diversified portfolio of stocks and bonds has survived every 30-year period in U.S. market history with a 4% initial withdrawal rate. To use it, simply multiply your expected annual retirement expenses by 25.

The 4% rule is not perfect — it was developed using historical data that may not predict the future, and it assumes a roughly 50/50 stock-bond allocation. However, it remains an excellent starting point for estimating your target. For a more personalized calculation, try our Retirement Calculator.

Breaking Down Your Retirement Expenses

To know how much you need, you first need to know how much you will spend. Many people assume they will spend less in retirement, but the reality is more nuanced. Some expenses decrease (commuting, work clothes) while others increase (healthcare, travel, hobbies).

A typical retirement expense breakdown looks like this:

• Housing (30–35%) — Mortgage or rent, property taxes, maintenance, utilities
• Healthcare (15–20%) — Premiums, copays, long-term care, dental, vision
• Food (10–15%) — Groceries and dining out
• Transportation (10–15%) — Even without a commute, you still need a car, insurance, and fuel
• Discretionary (15–20%) — Travel, entertainment, gifts, hobbies
• Other (5–10%) — Insurance, personal care, subscriptions, unexpected expenses

Important: Healthcare costs tend to rise significantly as you age. Fidelity estimates that an average 65-year-old couple retiring in 2026 may need roughly $315,000 or more for healthcare and medical expenses throughout retirement, even with Medicare coverage.

Social Security: How It Fits In

Social Security is designed to replace roughly 40% of pre-retirement income for average earners, though the exact amount depends on your earnings history and the age at which you claim benefits. You can start claiming as early as age 62, but your monthly benefit increases for each year you delay until age 70.

Delaying Social Security from 62 to 70 can increase your monthly benefit by roughly 77%. For many retirees, this makes delaying a powerful strategy — especially if you have other savings to draw from in the early years of retirement.

Keep in mind that Social Security benefits may be subject to taxation if your combined income exceeds certain thresholds. Up to 85% of your benefits can be taxable depending on your filing status and income level.

Tax-Advantaged Accounts and Their Role

Where you hold your retirement savings matters nearly as much as how much you save. Different accounts offer different tax treatments, and using them strategically can significantly reduce your lifetime tax burden.

• Traditional 401(k) and IRA — Contributions are tax-deductible today, but withdrawals in retirement are taxed as ordinary income. Best if you expect to be in a lower tax bracket in retirement.
• Roth 401(k) and Roth IRA — Contributions are made with after-tax dollars, but qualified withdrawals are completely tax-free. Best if you expect your tax rate to be the same or higher in retirement.
• Health Savings Account (HSA) — Often called the "triple tax advantage" account: contributions are tax-deductible, growth is tax-free, and withdrawals for medical expenses are also tax-free. After age 65, it functions like a Traditional IRA for non-medical withdrawals.

A well-structured retirement plan uses a mix of these accounts to give you flexibility in managing taxable income during retirement. Use our 401k Calculator to see how different contribution strategies can grow over time.

Sequence of Returns Risk

One of the most underappreciated dangers in retirement planning is sequence of returns risk. This is the risk that poor market returns occur early in your retirement, right when you begin making withdrawals. Even if average returns over your retirement period are perfectly fine, a bad sequence can devastate your portfolio.

Consider two retirees who each have $1 million and withdraw $40,000 per year. Both experience average annual returns of 7% over 25 years. However, one experiences strong returns in the first decade and weak returns later, while the other experiences the opposite. The retiree with strong early returns may end up with hundreds of thousands of dollars more — simply because the timing was different.

This is why maintaining a cash buffer, being flexible with withdrawals during down markets, and holding some bonds can be so important. It is also a strong argument for using guaranteed income sources like annuities to cover essential expenses. Our Annuity Calculator can help you estimate how much guaranteed income a given amount of savings could generate.

Monte Carlo Simulation: Planning for Uncertainty

Financial planners increasingly use Monte Carlo simulations to stress-test retirement plans. Instead of assuming a single average rate of return, a Monte Carlo simulation runs thousands of scenarios using randomized sequences of market returns based on historical volatility and correlation patterns.

The output is typically a probability of success — the percentage of simulated scenarios in which your portfolio survives your entire retirement. A plan with an 85% success rate means that in 85 out of 100 simulated futures, you did not run out of money.

While Monte Carlo analysis is not a guarantee, it provides a much more realistic picture of retirement risk than a single fixed return assumption. The key takeaway is that planning for a range of outcomes is far more useful than planning for one average outcome.

The Impact of Inflation

Inflation is the silent eroder of retirement savings. At an average inflation rate of 3%, the purchasing power of $1 million today will be roughly $553,000 in 20 years. This means your retirement number must account for the fact that everything will cost more in the future.

1. Your withdrawal amount grows each year — If you need $60,000 in your first year of retirement and inflation runs at 3%, you will need about $80,635 in year 10 and $108,367 in year 20
2. Conservative portfolios are more vulnerable — If you hold mostly bonds or cash, your returns may not keep pace with inflation, meaning your real (inflation-adjusted) portfolio value declines even if the nominal value stays the same
3. Social Security has COLA adjustments — Social Security benefits are adjusted annually for cost-of-living increases, which provides some inflation protection
4. Healthcare inflation outpaces general inflation — Medical costs have historically risen faster than the overall consumer price index, making healthcare planning especially important

How to Calculate Your Personal Retirement Number

Here is a step-by-step approach to finding your number:

1. Estimate your annual retirement expenses — Use your current spending as a baseline and adjust for expected changes in retirement
2. Subtract guaranteed income — Subtract expected Social Security benefits, pension income, or annuity payments
3. Multiply the gap by 25 — This applies the 4% rule to determine your target portfolio size
4. Adjust for your retirement timeline — If you plan to retire early or expect a longer-than-average lifespan, consider using a 3% or 3.5% withdrawal rate instead of 4%
5. Factor in inflation — If retirement is many years away, increase your target to account for the rising cost of living
6. Review and update annually — Your number will change as your income, expenses, and market conditions evolve

Retirement planning is not a one-time exercise. The most successful retirees revisit their plan regularly, adjust their savings rate when possible, and remain flexible about their retirement date and spending. Start with the frameworks above, use the available calculators to model your specific situation, and refine your plan as you get closer to retirement.