How much belongs in each asset
at your target weights?

A growing holding can also increase portfolio risk

Stocks, bonds and cash do not change in value at the same pace. Even a portfolio starting at 60% stocks, 30% bonds and 10% cash can become more exposed to stock-market movements after a stock rally. Check how far today’s weights have drifted from your chosen allocation.

Asset allocation sets how much to hold in each asset class; rebalancing adjusts weights after they change. Returning to a target does not eliminate losses or guarantee returns. It helps manage exposure in line with your goals and investment horizon.

Buffett specified weights as well as investments

In his 2013 Berkshire Hathaway shareholder letter, Warren Buffett described instructions for money left in trust for his wife: 90% in a very low-cost S&P500 index fund and 10% in short-term government bonds. This is an allocation for money serving a specific purpose.

Those weights are neither Buffett’s complete portfolio nor a universal allocation. The lesson here is to choose weights for the purpose of the money. Your goals, spending timeline and capacity for losses may call for a different mix.

Source: Berkshire Hathaway 2013 shareholder letter

The Gates Foundation Trust holds multiple types of investments

The 2024 audited statements of the Gates Foundation Trust, whose trustee is Microsoft co-founder Bill Gates, report equities, fixed income and private investments. The trust manages assets that support the foundation’s work and is distinct from Gates’s complete personal wealth.

This illustrates the use of multiple asset types for a long-term purpose. The disclosures do not establish personal trading motives or a fixed rebalancing schedule. Use the example to examine your own exposure to asset classes rather than copy a famous investor’s holdings.

Source: Gates Foundation Trust 2024 audited financial statements · Roles of the trust and foundation

New contributions change the adjustments needed

This example starts with stocks of $70,000, bonds of $20,000 and cash of $10,000, with target weights of 60:30:10.

New contributions can go toward underweight assets and reduce the amount that needs to be sold. A contribution may still be insufficient to reach the exact target without selling, as in this example. The figures are changes in target holdings before transaction costs and taxes.

Compare current market values on a consistent basis

Enter current market values rather than original purchase costs. The total investment is the amount you want allocated after adjustment. For a planned contribution, include it in that total while keeping current holdings at their pre-contribution values. If the money is already included in current cash, keep both total and holdings on the same basis to avoid counting it twice.

You can review weights on a schedule or when they move outside chosen limits. This calculator does not select a review frequency or allocation; it calculates changes for your chosen weights. Actual trades also depend on trading units, taxes, fees and the assets held.

Source: SEC — asset allocation and rebalancing

Target allocation amounts

Each asset-class target equals the total investment multiplied by its stock, bond, or cash weight.

Amounts to buy or sell

When all current holdings are entered, a shortfall is shown as buy and an excess is shown as sell.

What this calculator does not recommend

This tool converts your chosen weights into amounts. It does not recommend an allocation, forecast returns, or recommend trades.

Rebalancing $100,000 to 60:30:10

This example starts with $50,000 in stocks, $35,000 in bonds, and $15,000 in cash.

Stocks 60%

Buy $10,000

Bonds 30%

Sell $5,000

Cash 10%

Reduce $5,000

Moving the $10,000 excess from bonds and cash to stocks brings the portfolio closer to the chosen weights while keeping the same total value.

Frequently asked questions