Portfolio Rebalancing Calculator

Why Rebalance?

Different asset classes grow at different rates, so a portfolio that started at your target allocation drifts over time — a strong year for stocks, for instance, leaves you with more stock exposure (and more risk) than you originally intended. Rebalancing means selling some of what's grown and buying more of what's lagged, bringing your allocation back to your original target and, in the process, systematically selling high and buying low.

How to Use This Calculator

List each asset class in your portfolio, its current dollar value, and your target percentage for it. Your target percentages should add up to 100%. The calculator tells you exactly how much to buy or sell of each to get back on target.

How We Calculate It

Total portfolio value is the sum of all your current values. Each asset's target dollar value = total portfolio value × its target percentage. The difference between that target value and its current value is what you need to buy (if positive) or sell (if negative) to hit your target allocation.

A Few Notes

This calculator doesn't account for taxes — selling appreciated assets in a taxable account can trigger capital gains, so rebalancing inside tax-advantaged accounts (like a 401(k) or IRA) first, or rebalancing with new contributions instead of selling, can reduce or avoid that cost entirely. It also doesn't factor in trading costs or minimum investment amounts, which can matter for smaller portfolios or less liquid holdings.