Retirement Calculator
Calculate how much you need to retire. Enter your current savings, monthly contributions, expected return, and retirement age to project your nest egg and
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Formula
Where FV = Future Value at retirement, PV = Present Value (current savings), r = Annual expected return rate (decimal), t = Years until retirement, PMT = Monthly contribution. The 4% rule income is calculated as FV × 0.04 / 12 for monthly income. Inflation-adjusted value divides the future value by (1 + inflation)^t.
Last reviewed: January 2026
Worked Examples
Example 1: Starting at 30 with Moderate Savings
Example 2: Late Start at 45
Background & Theory
The Retirement Calculator — Plan Your Future applies the following established principles and formulas. Retirement savings planning integrates the mathematics of compound growth, tax optimization, inflation adjustment, and withdrawal sustainability. Compound growth over long time horizons is transformative: at a 7 percent real annual return, a sum doubles approximately every 10.3 years (the rule of 72 states that doubling time in years equals 72 divided by the annual growth rate). Starting early is therefore far more valuable than contributing larger amounts later, because early contributions benefit from the maximum number of compounding periods. Tax-advantaged accounts amplify accumulation. Traditional 401(k) and IRA contributions are made pre-tax, reducing current taxable income and allowing the full contribution to compound until withdrawal in retirement when the funds are taxed as ordinary income. Roth accounts accept after-tax contributions but grow and distribute entirely tax-free, advantageous for those expecting higher marginal rates in retirement. Contribution limits and income phase-outs are set by Congress and adjusted periodically for inflation. The four percent rule, derived from William Bengen's 1994 research and later corroborated by the Trinity Study (Cooley, Hubbard, and Walz, 1998), holds that a retiree can withdraw four percent of the initial portfolio value annually — adjusted each year for inflation — with a high probability of not outliving a 30-year retirement using a balanced equity/bond portfolio. The rule embeds assumptions about historical US market returns and does not guarantee success in low-return environments. Sequence-of-returns risk describes the danger that poor market performance early in retirement permanently impairs a portfolio even if long-run average returns are acceptable. Because withdrawals lock in losses during downturns, the order of returns matters enormously when cash flows are negative. The Social Security benefit formula replaces a progressive percentage of Average Indexed Monthly Earnings, providing a longevity-insured, inflation-adjusted base income that substantially reduces sequence-of-returns exposure. Real (inflation-adjusted) returns matter far more than nominal returns for retirement planning, since purchasing power preservation is the ultimate objective.
History
The history behind the Retirement Calculator — Plan Your Future traces back through the following developments. Before formal pension systems, retirement security depended almost entirely on personal savings, land, or family support. The first significant employer-sponsored pensions appeared in the railroad industry in the United States during the 1870s and 1880s. The American Express Company established a formal pension plan in 1875, widely cited as the first US corporate pension. Prussia established a state contributory pension system in 1889 under Chancellor Bismarck, a model that influenced welfare state development across Europe. In the United States, the Social Security Act of 1935, signed by President Franklin Roosevelt during the Great Depression, created a compulsory federal insurance program providing income to retired workers aged 65 and older. Initially funded on a pay-as-you-go basis, Social Security has been amended dozens of times; the 1983 Greenspan Commission reforms raised the retirement age and subjected benefits to partial income taxation to restore long-term solvency. The Employee Retirement Income Security Act of 1974 (ERISA) established fiduciary standards, vesting rules, and insurance for private-sector defined benefit pension plans through the Pension Benefit Guaranty Corporation. ERISA aimed to protect workers from the pension fund mismanagement and corporate failures that had left many retirees without promised benefits. Section 401(k) was added to the Internal Revenue Code in the Revenue Act of 1978, initially intended to allow deferred compensation arrangements. Benefits consultant Ted Benna identified in 1980 that the provision could be used to create employer-matched employee savings accounts. The 401(k) plan proliferated rapidly through the 1980s, and the broader shift from defined benefit to defined contribution plans accelerated as employers sought to reduce pension obligations. By the early 2000s, defined contribution plans had surpassed defined benefit plans as the primary private retirement savings vehicle in the United States, transferring investment risk from employers to individual workers and giving rise to the financial planning industry focused on retirement income adequacy.
Frequently Asked Questions
Reviewed by Sahil, Senior Finance & Tax Editor · Editorial policy
Retirement Calculator Formula
FV = PV(1 + r/12)^(12t) + PMT × [(1 + r/12)^(12t) - 1] / (r/12)
Where FV = Future Value at retirement, PV = Present Value (current savings), r = Annual expected return rate (decimal), t = Years until retirement, PMT = Monthly contribution. The 4% rule income is calculated as FV × 0.04 / 12 for monthly income. Inflation-adjusted value divides the future value by (1 + inflation)^t.
Retirement Calculator — Worked Examples
Example 1: Starting at 30 with Moderate Savings
Problem: A 30-year-old has $50,000 saved and contributes $500/month at 7% return until age 65. Inflation is 3%. What can they expect at retirement?
Solution: Years to retirement: 65 - 30 = 35 years\nFV of $50,000: $50,000 x (1.005833)^420 = $50,000 x 11.42 = $571,149\nFV of $500/month: $500 x ((1.005833^420 - 1) / 0.005833) = $500 x 1,787.66 = $893,830\nTotal: $571,149 + $893,830 = $1,464,979\n4% rule annual income: $1,464,979 x 0.04 = $58,599\nInflation-adjusted value: $1,464,979 / (1.03^35) = $520,900
Result: Retirement Savings: $1,464,979 | Monthly Income (4% rule): $4,883 | Inflation-Adjusted: $520,900
Example 2: Late Start at 45
Problem: A 45-year-old has $100,000 saved, contributes $1,000/month at 7% return until age 65. Inflation is 3%.
Solution: Years to retirement: 65 - 45 = 20 years\nFV of $100,000: $100,000 x (1.005833)^240 = $100,000 x 4.039 = $403,873\nFV of $1,000/month: $1,000 x ((1.005833^240 - 1) / 0.005833) = $1,000 x 520.93 = $520,927\nTotal: $403,873 + $520,927 = $924,800\n4% rule annual income: $924,800 x 0.04 = $36,992\nInflation-adjusted value: $924,800 / (1.03^20) = $512,049
Result: Retirement Savings: $924,800 | Monthly Income (4% rule): $3,083 | Inflation-Adjusted: $512,049
Retirement Calculator — Frequently Asked Questions
What is the 4% rule for retirement withdrawals?
The 4% rule is a retirement planning guideline developed by financial planner William Bengen in 1994. It states that retirees can withdraw 4% of their portfolio in the first year of retirement, then adjust that amount for inflation each subsequent year, with a very low probability of running out of money over a 30-year retirement period. For example, with a $1 million portfolio, you would withdraw $40,000 in year one. If inflation is 3%, you would withdraw $41,200 in year two. The rule assumes a diversified portfolio of roughly 50-75% stocks and 25-50% bonds. While widely used, critics note that it was based on historical US market returns, may be too conservative in strong markets, and does not account for variable spending patterns that most retirees actually follow.
How does inflation affect my retirement savings?
Inflation erodes the purchasing power of your money over time, which is critical for retirement planning since your savings may need to last 20-30+ years. At 3% annual inflation, $100 today will have the purchasing power of only $55 in 20 years and $41 in 30 years. This means that if you retire with $1 million, you would need nearly $2.5 million in 30 years to maintain the same lifestyle. To combat inflation, your retirement portfolio should include growth assets like stocks and real estate that historically outpace inflation. Treasury Inflation-Protected Securities (TIPS) and I-bonds also provide direct inflation protection. When planning, always consider your real (inflation-adjusted) rate of return, not just the nominal return.
When should I start saving for retirement?
The best time to start saving for retirement is as early as possible, ideally in your 20s when you begin earning income. Starting early gives you the enormous advantage of compound interest working over decades. Consider this: saving $300/month starting at age 25 at a 7% return yields approximately $791,000 by age 65. Waiting until age 35 to start the same savings produces only about $366,000 — less than half, despite only a 10-year difference. If you are starting late, do not be discouraged — saving aggressively now is still far better than not saving at all. Maximize employer 401(k) matches first (it is free money), then contribute to IRAs and additional retirement accounts. Those over 50 can take advantage of catch-up contribution limits to accelerate their savings.
What rate of return should I expect for retirement planning?
For long-term retirement planning, most financial advisors suggest using a 6-8% average annual return before inflation, or 3-5% after inflation. The S&P 500 has historically returned about 10% annually before inflation and roughly 7% after inflation over long periods. However, a diversified retirement portfolio typically includes bonds and other lower-return assets, bringing the blended average down to 6-8%. When you are far from retirement (20+ years away), you can use the higher end of the range since your portfolio will likely be more stock-heavy. As you approach retirement, shift to more conservative estimates of 4-6% as your allocation moves toward bonds. Always run scenarios with different return assumptions to stress-test your retirement plan and prepare for less favorable market conditions.
What is the difference between a traditional and Roth retirement account?
Traditional 401(k) and IRA contributions reduce your taxable income today — a $6,500 contribution in the 22% bracket saves $1,430 in taxes immediately — but all withdrawals in retirement are taxed as ordinary income. Roth accounts accept after-tax contributions with no upfront deduction, but qualified withdrawals (age 59½+, account held 5+ years) are completely tax-free, including all growth. If you expect to be in a higher tax bracket in retirement than today, Roth wins. If you expect lower rates in retirement, traditional wins. Many advisors suggest holding both types to give yourself tax flexibility when withdrawing. Roth IRAs also have no required minimum distributions (RMDs), unlike traditional accounts.
Is my data stored or sent to a server?
No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.