Calculators
Portfolio Rebalancing Calculator
Calculate current portfolio weights and the buy or sell amount for each holding to return to your target allocation.
- Runs in your browser
- Nothing uploaded
The tool
Enter your numbers below. Results update as you type, and nothing leaves your browser.
Everything you enter stays on your own machine. Nothing is sent to us or to anyone else, which you can confirm in your browser network tab.
What people use it for
- Annual portfolio reviews
- Investing a lump sum into an existing portfolio
- Checking drift after a market move
- Managing a family member's accounts
About this tool
What the Portfolio Rebalancing Calculator does
Over time, winners grow to take up more of a portfolio than intended, raising its risk. Rebalancing sells some of what has grown and buys what has lagged to restore your target weights. Adding new cash first can reduce how much you need to sell.
Formula
- Current weight = holding value ÷ portfolio value
- Target value = (portfolio + new money) × target weight
- Trade = target value − current value
Worked example
Using the starting values in the calculator above:
| Input | Value |
|---|---|
| Holdings | 4 entries |
| New money to invest | $0.00 |
| Result | Value |
|---|---|
| Largest drift from target | 6.4% |
| Total to sell | $7,000 |
| Total to buy | $7,000 |
| Portfolio after new money | $110,000 |
How to read the result
Many investors rebalance once a year or when a holding drifts more than about five percentage points from target, rather than constantly.
In taxable accounts, direct new contributions to underweight holdings first to avoid realising gains.
For education only, not investment advice. Past returns do not guarantee future results.
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Questions
Questions about this tool
The things clients actually want to know — costs, timelines, ownership and what happens after launch.
Once a year or when allocations drift by a set threshold are both common approaches.
Selling winners in taxable accounts can realise capital gains; rebalancing inside tax-advantaged accounts avoids that.
To keep the portfolio's risk in line with the allocation you chose.
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