Investment Portfolio Calculator

Portfolio rebalancing is the process of bringing your investment portfolio back to your target asset allocation. Over time, different assets grow or fall at different speeds. For example, if stocks rise sharply while bonds remain flat, your portfolio may become more stock-heavy than you originally planned. A portfolio rebalancing calculator helps you compare your current allocation with your target allocation and estimate how much you may need to buy or sell.

This investment portfolio calculator is designed for investors who want a simple asset allocation calculator without uploading private financial data to a server. You can enter categories such as U.S. stocks, Canadian stocks, international stocks, Korean stocks, bonds, cash, REITs, commodities, crypto, or any custom asset class. The calculator instantly updates your current portfolio weight, doughnut chart, target value, difference, and rebalancing action.

Rebalancing is important because it helps keep your investment risk aligned with your original plan. Without rebalancing, a portfolio can slowly drift into a risk level that no longer matches your goals. A conservative investor may become overexposed to stocks after a long bull market, while a growth-focused investor may become too defensive after moving too much money into cash or bonds.

Rebalancing also creates a disciplined investment habit. Instead of making emotional decisions based on market headlines, you follow a structured process. When one asset has grown far above its target, the calculator may show a Sell amount. When another asset has fallen below its target, the calculator may show a Buy amount. In this way, rebalancing can encourage systematic “sell high and buy low” behavior.

For most long-term investors, a practical strategy is to use a hybrid approach: review the portfolio on a regular schedule and rebalance only when allocation drift becomes meaningful. This avoids overtrading while still keeping the portfolio aligned with your long-term investment plan.

A simple example is to review your portfolio every three or six months and rebalance if any major asset class is more than 5 percentage points away from its target. Conservative investors may choose a tighter band, while aggressive investors may allow wider drift. Investors in taxable accounts should also consider capital gains taxes, transaction fees, and bid-ask spreads before selling.

The calculator first adds up all current asset values to determine your total portfolio value. Then it calculates each asset’s current percentage of the portfolio. Next, it multiplies the total portfolio value by each asset’s target percentage to estimate the ideal target value. Finally, it compares the target value with the current value and shows the difference as a Buy, Sell, or Hold action.