Bond Allocation by Age

When constructing an investment portfolio, one of the most widely referenced guidelines is the "age in bonds" rule. This classic approach suggests that the percentage of your portfolio allocated to bonds should roughly equal your age. For example, if you are 40 years old, you would hold 40% of your investments in bonds, with the remaining 60% in stocks and other growth assets. Over time, this rule has evolved, with some modern advisors recommending more aggressive variations such as "age minus 10" or even "age minus 20" in bonds, to account for longer lifespans and changing risk tolerances.

The formula for calculating your bond allocation using the classic rule is:

For more aggressive variations, you might use:

or

Use these formulas as a practical starting point for deciding how much of your portfolio to dedicate to bonds at any age.

These formulas are designed to help you gradually reduce risk as you get older. The rationale is straightforward: as you approach retirement and will soon need to draw from your investments, it makes sense to reduce your exposure to the volatility of stocks and increase the stability of bonds. Younger investors have more time to recover from market downturns, so they can afford a higher allocation to stocks. As you age, shifting more into bonds can help preserve capital and provide more predictable income, making your portfolio less vulnerable to market swings just as you begin to rely on it for living expenses.