Asset Allocation Calculator United States

What the asset allocation calculator does

The asset allocation calculator suggests how to divide a portfolio between stocks and bonds. It uses a well-known age-based rule of thumb and adjusts the result for how much risk you are comfortable with. The output shows the target percentage for each asset class and the dollar amount it represents on your portfolio.

The split between broad asset classes usually drives more of a portfolio’s long-run behavior than the specific funds chosen within each class, and a written target makes it easier to stick to a plan when markets move.

How the age-based rule works

The rule sets your stock percentage to a base number minus your age. The base was traditionally 100, but as life expectancy has grown many advisors use 110 or 120, which keeps more money in stocks for longer to fund a longer retirement. The tool stores the base as a parameter.

A young investor has decades before needing the money and can ride out stock market swings in exchange for higher expected growth. An older investor has less time to recover from a downturn, so the rule moves weight from stocks toward bonds, which are generally steadier. Subtracting your age from the base makes that shift happen gradually over your investing life.

Adjusting for risk tolerance

Two people of the same age can have very different appetites for risk, so a risk tolerance setting tilts the result:

• Conservative shifts the mix ten points toward bonds, for investors who want smaller swings and accept lower expected returns.
• Moderate uses the age-based rule as is.
• Aggressive shifts the mix ten points toward stocks, for investors with a long horizon and a high tolerance for volatility.

How you feel when your portfolio falls is a real constraint. An allocation you can hold through a downturn is better than a theoretically better one you abandon at the worst moment.

Reading your result

• The stock (equity) percentage.
• The bond (fixed income) percentage.
• The dollar amount to hold in stocks.
• The dollar amount to hold in bonds.

The dollar figures tell you how much to buy, sell or move when you rebalance. If your current holdings differ from the targets, the gap shows what to adjust.

Stocks versus bonds

Stocks are ownership in companies and have historically returned more over the long run, with larger swings in value. Bonds are loans to governments or companies that pay interest; they tend to be more stable and usually grow more slowly. When stocks fall, high-quality bonds often hold their value or rise, which cushions the portfolio.

Within each slice, most investors use low-cost, diversified funds instead of individual securities, which reduces the risk tied to any single company. The calculator covers only the top-level split; how you fill each part is a separate decision.

Rebalancing over time

As markets move, a portfolio drifts away from its targets. A strong run in stocks can leave you holding more equity than you intended, which raises your risk. Rebalancing means selling some of what has grown and buying more of what has lagged to return to your target. Many investors do this once a year or when an asset class drifts past a set threshold, and re-running this calculator as you age gives you an updated target.

Limitations

The age-based rule does not know your goals, your job security, your pension or Social Security income, or the size of your emergency fund. Two investors of the same age and risk tolerance might reasonably choose different allocations if one expects a stable pension and the other relies entirely on a portfolio. The rule also treats all stocks as one block and all bonds as another, ignoring choices such as domestic versus international stocks or short versus long-duration bonds. Use the suggested split as a starting point, adjust it for the rest of your finances, and check it against how much of a bad year you could tolerate.

This is general information only and not investment advice. Consider your full financial situation and consult a qualified professional before making investment decisions.

About This Asset Allocation Calculator

Use this asset allocation calculator to get an instant, accurate estimate. The figures follow official guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.