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Portfolio rebalancing calculator
Enter what you hold and the weights you want. The calculator shows how far each holding has drifted and the buys and sells that would bring it back.
Last reviewed
Educational tool, not investment advice. It does plain arithmetic on the numbers you type, uses no market data, and makes no forecast. Your entries stay in this page and are never sent anywhere.
Your holdings
Amounts can be in any one currency. The rows below start with an invented example; replace it with your own numbers.
Holding 1
Holding 2
Holding 3
Targets add up to 100.0%
Drift and trades
2 of 3 holdings drifted 5.0 pp or more. The largest drift is 13.0 pp. Rebalancing buys 1,300.00 and sells 1,300.00.
| Holding | Value now | Weight now | Target | Drift | Trade | Weight after |
|---|---|---|---|---|---|---|
| Holding A | 6,200.00 | 62.0% | 50.0% | +12.0 pp (at or above the flag level) | Sell 1,200.00 | 50.0% |
| Holding B | 3,100.00 | 31.0% | 30.0% | +1.0 pp | Sell 100.00 | 30.0% |
| Holding C | 700.00 | 7.0% | 20.0% | -13.0 pp (at or above the flag level) | Buy 1,300.00 | 20.0% |
| Total | 10,000.00 | 100.0% | 100.0% | Buy 1,300.00, sell 1,300.00 | 100.0% |
Positive drift means a holding is above its target weight. Amounts are exact and ignore fees, spreads, taxes and whole-share rounding, which change what you can actually trade.
How the numbers are worked out
Each holding's current weight is its value divided by the total of all holdings. Drift is that weight minus the target, in percentage points. To rebalance with a buy and sell, the target value of a holding is its target weight times (the total plus any new cash), and the trade is the target value minus what you hold. With buy only, nothing is sold: the new cash goes first to the most underweight holdings until they catch up with the rest, so the result can fall short of the targets when the cash is small.
Rebalancing returns a portfolio to the risk level you chose; it does not aim at a higher return. Read what portfolio drift is and how often to rebalance for the reasoning, and the glossary for the terms.
When you do not want to do this by hand
Acubic runs this comparison for a connected eToro or Trading 212 account on a schedule you set, prepares the smallest set of orders that closes the gap, and, unless you choose Full Automatic, waits for your approval before sending them. It reads live positions and sizes orders in shares, so its figures will differ from this calculator's exact amounts. See the use cases for worked scenarios.
This tool and its text are educational. They are not investment, tax or legal advice, and nothing here predicts how any investment will perform.