Portfolio Rebalancing Calculator
Enter your current holdings and target percentages to see exactly how much of each asset to buy or sell to rebalance.
Frequently Asked Questions
What is rebalancing?
Adjusting your holdings back to a target mix (e.g. 60% stocks / 40% bonds) after market moves push them out of balance. It controls risk and enforces buy-low/sell-high discipline.
How often should I rebalance?
Common approaches are once a year or whenever an allocation drifts more than 5% from its target. There is no single right answer.
Does rebalancing cost anything?
It can trigger trading fees and capital gains taxes in a taxable account, so weigh those before selling.
Understanding the Portfolio Rebalancing Calculator
Over time, market movements push a portfolio away from its target asset allocation — winners grow into an oversized share while laggards shrink. This calculator compares your current holdings against your target percentages and shows the exact buy and sell amounts needed to restore the plan. It is for long-term investors, retirement savers, and anyone maintaining a stock/bond/cash mix across accounts. Results are educational estimates that ignore taxes and transaction costs unless you account for them separately; they are not a recommendation to buy or sell any specific security.
How it works
Enter each asset class (e.g., US stocks, international stocks, bonds, cash), its current value, and your target allocation percentage. The calculator sums your total portfolio, computes each asset's current weight, and finds the dollar gap between current and target values. Positive gaps mean buy; negative gaps mean sell. You can rebalance by selling overweight assets to buy underweight ones, or — often more tax-efficient — by directing new contributions toward underweight assets. The tool reports target dollar value, current value, and the trade for each line so the weights return to plan. Always confirm targets sum to 100%.
Worked example
Your $100,000 portfolio targets 60% stocks / 40% bonds, but a strong year leaves you at $70,000 stocks and $30,000 bonds (70/30). Target values are $60,000 stocks and $40,000 bonds. The trades: sell $10,000 of stocks and buy $10,000 of bonds to return to 60/40. If you prefer to avoid realizing gains, you could instead steer the next $10,000+ of new contributions into bonds until the mix rebalances naturally.
Tips & common mistakes
- Selling in a taxable account can trigger capital gains tax; rebalancing inside IRAs or 401(k)s avoids that, and new contributions can rebalance without selling.
- Many investors rebalance on a schedule (annually) or by threshold (when an asset drifts 5+ percentage points off target) — both are reasonable.
- Confirm your target percentages add up to exactly 100% or the trade amounts will be off.
- Factor in transaction costs and bid-ask spreads before making many small trades.
- Rebalancing controls risk by trimming what has grown; it is not a tactic to chase performance.
Sources & methodology
- • U.S. SEC Investor.gov — Asset Allocation and Rebalancing (https://www.investor.gov/introduction-investing/investing-basics/how-stock-markets-work/asset-allocation)
- • FINRA — Rebalancing Your Portfolio (https://www.finra.org/investors/insights/rebalancing-your-portfolio)
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Reviewed by the TopOpenTools editorial team · Last updated June 2026. These tools provide general estimates for educational purposes only and are not financial, tax, insurance, investment, or medical advice. Verify important decisions with a qualified professional.