Portfolio Rebalancing Calculator
Shows exactly how much of each asset class to buy or sell to restore your portfolio to its target allocation. Use it after significant market moves drift your holdings away from your intended risk level.
About this calculator
Portfolio rebalancing restores your asset mix to its intended weights after market price movements cause drift. The core calculation for the stock adjustment is: Stock Adjustment ($) = (Total Portfolio Value × Target Stock Allocation%) − Current Stock Value. A positive result means you need to buy more stocks; a negative result means you should sell. Drift occurs because different assets grow at different rates — equities may surge while bonds lag, pushing your allocation beyond its target. Most financial advisors recommend rebalancing when any asset class drifts more than 5 percentage points from its target, or on a scheduled basis (e.g., annually). Rebalancing enforces a disciplined buy-low, sell-high behavior by systematically trimming outperformers and adding to underperformers.
How to use
Suppose your total portfolio is $100,000. Current stock value is $75,000 and your target stock allocation is 60%. Step 1 — Enter Total Portfolio Value: $100,000. Step 2 — Enter Current Stock Value: $75,000. Step 3 — Enter Target Stock Allocation: 60%. Step 4 — Adjustment = ($100,000 × 60%) − $75,000 = $60,000 − $75,000 = −$15,000. The negative result means you need to sell $15,000 worth of stocks and reallocate that capital to bonds or other underweight asset classes to restore your 60/40 target.
Frequently asked questions
How often should I rebalance my investment portfolio?
Most research supports rebalancing either on a calendar schedule (annually or semi-annually) or when allocations drift beyond a set threshold — commonly 5 percentage points. Calendar rebalancing is simple to implement but may trigger unnecessary trades in calm markets. Threshold-based rebalancing is more responsive to volatile conditions but requires regular monitoring. A hybrid approach — checking annually but only rebalancing if drift exceeds the threshold — tends to balance simplicity and efficiency effectively.
What are the tax implications of rebalancing a taxable investment portfolio?
Selling appreciated assets in a taxable account triggers capital gains taxes, which can erode the benefit of rebalancing. Short-term gains (assets held under one year) are taxed as ordinary income, while long-term gains receive preferential rates of 0%, 15%, or 20% depending on your income. To minimize taxes, consider rebalancing first within tax-advantaged accounts like IRAs or 401(k)s, directing new contributions toward underweight assets, or using dividend reinvestment to gradually shift allocations. Tax-loss harvesting can also offset gains realized during rebalancing.
Why does portfolio drift happen and why does it matter for risk management?
Drift occurs because different asset classes generate different returns over time. A stock-heavy bull market can push an originally balanced 60/40 portfolio to 75/25, exposing you to more equity risk than intended. This matters because your original allocation was presumably chosen to match your risk tolerance and time horizon. An unrebalanced portfolio may suffer larger drawdowns during market downturns than you planned for. Regular rebalancing keeps your actual risk exposure aligned with your financial goals and personal comfort with volatility.