Income Replacement Calculator
Find out how large an investment portfolio you need to fully replace your salary with passive income by retirement. Essential for anyone planning financial independence or early retirement.
About this calculator
This calculator estimates the future portfolio value needed to sustain a target income stream indefinitely. It combines two financial principles: the safe withdrawal rate and the future value of money. First, the required portfolio at retirement is: neededPortfolio = (currentSalary × desiredReplacement%) / withdrawalRate%. For example, replacing $60,000/year at a 4% withdrawal rate requires a $1,500,000 portfolio. Second, that target is expressed in today's dollars grown to retirement age using the future value formula: FV = neededPortfolio × (1 + investmentReturn%)^(65 − currentAge). This accounts for investment growth between now and retirement, giving you the portfolio size in nominal future dollars. The safe withdrawal rate (commonly 4%, from the Trinity Study) represents the percentage you can withdraw annually without depleting your portfolio over a 30-year horizon.
How to use
Example: salary $80,000, 100% replacement, 4% withdrawal rate, 7% annual return, current age 35. Step 1 — Needed portfolio = ($80,000 × 1.00) / 0.04 = $2,000,000. Step 2 — Years to 65 = 65 − 35 = 30. Step 3 — Future value = $2,000,000 × (1 + 0.07)^30 = $2,000,000 × 7.6123 = $15,224,600. This means your investments need to grow to approximately $15.2 million in nominal terms by age 65 to safely replace your $80,000 salary, assuming 7% annual growth and a 4% withdrawal rate.
Frequently asked questions
What is a safe withdrawal rate and how does it affect how much I need to retire?
The safe withdrawal rate (SWR) is the percentage of your portfolio you can withdraw annually without running out of money over a long retirement. The most cited figure is 4%, derived from the Trinity Study analyzing historical U.S. stock and bond returns over 30-year periods. Using a lower SWR like 3% requires a larger portfolio but provides more security, especially for early retirees with a 40+ year horizon. A higher rate like 5% reduces the required portfolio but increases the risk of depleting funds in a market downturn.
How does my current age affect the income replacement target?
The younger you are, the more time your investments have to grow, which dramatically reduces how much you need to save today. The formula applies compound growth over (65 − currentAge) years, so a 35-year-old has 30 years of compounding versus only 10 years for a 55-year-old. This exponential effect means starting 10 years earlier can more than double the growth on the same invested principal. Early starters can also afford to take on slightly more investment risk, potentially accessing higher long-term returns.
What investment return should I use when calculating income replacement needs?
A commonly used conservative assumption for a diversified stock-and-bond portfolio is 6–7% annual nominal return, reflecting long-run historical U.S. market averages minus modest inflation. If you want real (inflation-adjusted) figures, use 4–5% instead and compare against today's purchasing power. Overly optimistic return assumptions (10%+) can lead to under-saving, leaving you short at retirement. It's wise to run the calculator at multiple return scenarios — 5%, 7%, and 9% — to understand the range of outcomes and plan conservatively.