Asset Allocation by Age: How to Build the Right Portfolio

What Is Asset Allocation and Why Does It Matter?

Asset allocation is the process of dividing your investment portfolio among different asset classes — primarily stocks (equities), bonds (fixed income), and cash or cash equivalents. Some investors also include alternative investments like real estate investment trusts (REITs), commodities, or cryptocurrencies.

The core principle is straightforward: different asset classes have different risk and return profiles, and they often move in opposite directions. When stocks drop sharply (as in 2008, 2020, or 2022), bonds typically hold steady or rise, cushioning your portfolio. When stocks surge, bonds provide lower returns but reduce volatility. The blend determines both your expected return and the maximum drawdown you are likely to experience.

Historical data makes the case clearly. From 1926 through 2025, US large-cap stocks returned approximately 10.3% annually, while US intermediate-term government bonds returned about 5.2%. A 100% stock portfolio grew dramatically over the long term but experienced drawdowns of 50% or more (the S&P 500 fell 57% from 2007 to 2009). A 60/40 stock/bond portfolio returned about 8.5% annually — only 1.8% less — but its maximum drawdown was roughly 30%, nearly half as severe. For most investors, giving up a small amount of return for dramatically less volatility is a worthwhile trade. Use our investment calculator to model how different allocations affect your portfolio growth over time.

Age-Based Asset Allocation: A Complete Table

Your age is the primary driver of allocation because it determines your investment time horizon — how many years your money will remain invested before you need to withdraw it. Young investors have decades for their portfolio to recover from downturns; retirees need stability because they are spending their portfolio.

The following table provides recommended allocation ranges for each decade of life. These are guidelines, not rigid rules — adjust based on your personal risk tolerance, income stability, and other assets.

Notice that even at age 70+, the recommended stock allocation is still 30% to 45%. This surprises many retirees, but it makes sense: a 70-year-old couple may live another 20 to 25 years. A portfolio that is too conservative risks running out of money due to inflation eroding purchasing power. The 4% withdrawal rule that many retirement plans use assumes a portfolio with significant stock exposure — a 100% bond portfolio historically fails the 4% rule far more often than a 60/40 portfolio.

The Rule of 110 (and Other Age-Based Formulas)

Simple formulas provide a quick starting point for determining your stock allocation:

• Rule of 110: Subtract your age from 110. A 35-year-old holds 75% stocks. A 65-year-old holds 45% stocks. This is the most commonly cited modern rule and aligns well with the table above.
• Rule of 100: The older version. Subtract your age from 100. A 35-year-old holds 65% stocks. More conservative — appropriate for very risk-averse investors or those with generous pensions covering living expenses.
• Rule of 120: Subtract your age from 120. A 35-year-old holds 85% stocks. More aggressive — appropriate for high earners with long time horizons and strong risk tolerance.

These formulas are starting points, not gospel. Your actual allocation should reflect:

• Risk tolerance: Can you emotionally handle watching your portfolio drop 30% or 40%? If a 2022-style bear market would cause you to panic-sell, your stock allocation is too high regardless of what the formula says.
• Income stability: A tenured professor or government employee with a defined-benefit pension can afford a more aggressive portfolio because their income is secure. A freelancer with volatile income may want more bonds for stability.
• Other assets: If you own rental properties or have a large pension, those function like bond-like assets in your overall financial picture, allowing your investment portfolio to be more stock-heavy.
• Spending timeline: Saving for a house down payment in 3 years? That money should be in bonds or cash regardless of your age. Retirement money 30 years out? Stock-heavy.

Target-Date Funds: Allocation on Autopilot

Target-date funds (also called lifecycle funds or retirement-date funds) are mutual funds that automatically adjust their asset allocation as you approach a target retirement year. You choose the fund closest to your expected retirement year — such as a 2055 fund if you plan to retire around 2055 — and the fund handles everything: stock-to-bond ratios, rebalancing, diversification, and the gradual shift toward more conservative holdings.

Target-date funds have become enormously popular, especially in 401(k) plans. Many employers now use them as the default investment option. The best target-date funds from Vanguard, Fidelity, and Schwab charge expense ratios of just 0.10% to 0.15% and hold broad-market index funds internally.

The glide path is the trajectory a target-date fund follows from aggressive to conservative over time. Different fund families use different glide paths, which can significantly affect outcomes. Vanguard's target-date funds reach their most conservative allocation (30% stocks / 70% bonds) seven years after the target date. Fidelity's reach their most conservative point (24% stocks) 10 to 19 years after. T. Rowe Price maintains higher stock allocations throughout, reaching 55% stocks at the target date and 30% stocks at age 95+.

The differences matter. During the 2008 financial crisis, target-date funds with the same target year lost anywhere from 9% to 41% depending on the fund family — a staggering range for products with the same name and target date. Always examine a fund's actual glide path and current allocation, not just the target year.

Use our retirement savings calculator to estimate how much you need to save regardless of which allocation approach you choose, and our 401(k) calculator to model contributions and employer matching.

Rebalancing Your Portfolio

Even the best initial allocation drifts over time as different asset classes earn different returns. A portfolio that starts at 70/30 stocks/bonds might become 80/20 after a year of strong stock performance. If you do not rebalance, your portfolio gradually becomes riskier than you intended — exactly the wrong direction as you age.

Rebalancing is the process of selling what has grown beyond its target weight and buying what has fallen below. There are two main approaches:

Calendar-based rebalancing: Set a schedule — once per year (often in January) or once per quarter — and rebalance on that date regardless of how far allocations have drifted. This is simple, easy to follow, and removes the temptation to time the market. Research shows that annual rebalancing captures most of the benefit.

Threshold-based rebalancing: Set bands around your target allocation (e.g., plus or minus 5 percentage points) and rebalance only when an asset class breaches its band. If your target is 70% stocks, rebalance when stocks exceed 75% or fall below 65%. This approach is slightly more tax-efficient because it avoids unnecessary transactions but requires you to monitor your portfolio regularly.

In taxable accounts, rebalancing creates taxable events — selling appreciated assets triggers capital gains. Strategies to minimize this tax cost include:

• Rebalance with new contributions: Direct new money into the underweight asset class instead of selling the overweight one.
• Rebalance in tax-advantaged accounts first: Sell and buy within your IRA or 401(k) where there are no tax consequences, then rebalance the taxable account only if needed.
• Use dividends: Direct dividends and interest to the underweight asset class rather than reinvesting them in the same fund.
• Pair with tax-loss harvesting: If an asset class is both overweight and at a loss, selling it achieves two goals simultaneously — rebalancing and generating a tax loss.

International vs Domestic Allocation

Within your stock allocation, how much should be in US stocks versus international stocks? This is one of the most debated questions in portfolio construction.

The global stock market capitalization is roughly 60% US and 40% international. A purely market-weight portfolio would hold those proportions. However, many advisors recommend a home bias of 60% to 70% US stocks and 30% to 40% international for American investors. The reasoning includes:

• US companies already earn roughly 40% of their revenue internationally, providing indirect global exposure
• Currency risk adds volatility to international holdings without always adding return
• US markets have been the strongest global performers over the past 15 years (though this was not the case from 2000 to 2010, when international stocks significantly outperformed)
• Tax efficiency — qualified dividends from US stocks receive preferential tax treatment that foreign dividends may not

International allocation should include both developed markets (Europe, Japan, Australia, Canada) and emerging markets (China, India, Brazil, Taiwan, South Korea). A common split within the international portion is 75% developed and 25% emerging. Emerging markets are more volatile but offer higher long-term growth potential as those economies expand.

The most important principle is diversification. Decades where US stocks dominated (2010–2024) are typically followed by decades where international stocks lead. Holding both ensures you participate in whichever region outperforms without needing to predict the future.

Bond Types by Age

Just as your stock-to-bond ratio should change with age, the types of bonds you hold should also evolve. Not all bonds carry the same risk — long-duration Treasury bonds can lose 20% or more in a rising rate environment (as investors learned in 2022), while short-term Treasury bills are virtually risk-free.

• Ages 20–40 (bonds as ballast): Your bond allocation is relatively small and serves primarily as a stabilizer during stock downturns. A total bond market index fund (like BND or AGG) works well. You can also consider a small allocation to TIPS (Treasury Inflation-Protected Securities) to hedge inflation.
• Ages 40–55 (growing the bond allocation): As bonds become a larger portion of your portfolio, consider diversifying across types. An intermediate-term bond index fund as the core, supplemented with some short-term bonds for stability. Avoid long-duration bonds, which add interest rate risk you do not need.
• Ages 55–65 (pre-retirement): Shift toward higher quality and shorter duration. A mix of short-term and intermediate-term government and investment-grade corporate bonds. TIPS become more important as inflation protection during the transition to retirement spending. Consider building a 2–3 year cash and short-term bond buffer for early retirement withdrawals.
• Ages 65+ (in retirement): Income generation and capital preservation are paramount. A bond ladder (individual bonds maturing in successive years) provides predictable cash flow. Short to intermediate-term bonds reduce interest rate risk. TIPS protect purchasing power. Some retirees add high-yield bonds (5–10% of bond allocation) for additional income, accepting the higher credit risk.

One common mistake is holding too much cash instead of bonds. Cash (savings accounts, money market funds) is appropriate for emergency funds and short-term needs, but for investment portfolios, bonds provide higher returns over time while still offering stability. Over the past 50 years, intermediate-term government bonds have outperformed cash by roughly 1.5% annually.

Risk Tolerance: The Personal Factor

All the age-based guidelines in the world cannot account for one critical variable: how you personally react to losses. Risk tolerance is partly emotional, partly circumstantial, and it dramatically affects whether you will stick with your allocation during downturns — which is when it matters most.

Ask yourself these questions to gauge your risk tolerance:

• If your portfolio dropped 30% in a month, would you: (a) buy more, (b) hold steady, or (c) sell some or all to stop the bleeding? If your honest answer is (c), your stock allocation is too high.
• Do you check your portfolio daily, weekly, monthly, or rarely? Frequent checkers tend to be more affected by volatility and may benefit from a more conservative allocation to reduce anxiety.
• Is your income stable or variable? If your job security is uncertain, a more conservative portfolio reduces the chance of needing to sell investments at a loss during a personal financial crisis.
• Do you have other safety nets — emergency fund, spouse's income, family support, insurance? More safety nets allow a more aggressive portfolio.

The best portfolio is not the one with the highest theoretical return — it is the one you will actually stick with through 30 to 40 years of bull markets, bear markets, crashes, and recoveries. A 70/30 portfolio you hold through every downturn will vastly outperform a 90/10 portfolio you panic-sell during every correction.

Frequently Asked Questions