Portfolio Rebalancing Calculator
Winners drift: a 60/40 portfolio quietly becomes 75/25 after a good run in stocks. Enter what you hold and what you want to hold — get the exact buy and sell amounts that put every holding back on target.
Your holdings
Rebalancing actions
| Holding | Current | Now | Target | Action |
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Why rebalance at all
Your allocation is a risk decision disguised as a pie chart. When stocks outperform, they silently claim a bigger slice — and your portfolio starts taking risks you never approved, usually right before the cycle turns. Rebalancing is the discipline of selling a little of what ran up and buying what lagged, restoring the risk level you chose on a calm day. Done consistently, it also enforces "buy low, sell high" without requiring you to predict anything.
Calendar vs threshold rebalancing
Two respectable approaches. Calendar rebalancing — once or twice a year, on a schedule — is simple, cheap, and easy to automate. Threshold rebalancing acts whenever any holding drifts more than about 5 percentage points from target, which responds faster in volatile markets but trades more often. Studies find the performance difference small; what matters is having a rule written down before markets get exciting, and following it instead of your gut.
Action = target $ − current $ (positive → BUY, negative → SELL)
Worked example
Five holdings worth $30,000 against targets of 40/25/15/12/8. Holding 1 sits exactly on target — no action. Holdings 2 and 3 ran hot: sell $500 each. Holdings 4 and 5 lagged: buy $600 and $400. Buys ($1,000) equal sells ($1,000), as they must when targets sum to 100% — rebalancing moves money between holdings; no new cash required.
Caveats worth knowing
- Taxable accounts: sell carefully. Every sale of a winner realizes capital gains. Prefer rebalancing inside 401(k)s and IRAs, or steer new contributions to underweight holdings instead of selling.
- Don't rebalance dust. Actions under a dollar are noise — this calculator shows "—" for those. Some investors set a minimum trade size to avoid fiddling.
- Zero-value rows are ignored in the totals, so you can model a 2- or 3-fund portfolio by leaving the rest at $0.