Last reviewed August 28, 2026

Portfolio Allocation Calculator: Formula, Scenarios & Interpretation

Compare current portfolio weights with target allocations and calculate approximate buy/sell amounts needed to rebalance.

What the calculation measures

Positive rebalance amounts indicate an underweight category; negative amounts indicate an overweight category under the selected targets.

How to interpret the result

Consider taxes, transaction costs and account constraints before making changes.

Run scenarios instead of one answer

Change the most uncertain input and compare outcomes. A calculator is most useful when it shows sensitivity, not when one estimate is treated as a guarantee.

Limits and assumptions

Target allocation is a personal investment-policy choice; the calculator does not recommend an allocation.

Try the browser tool

Work with your file locally.

Open Portfolio Allocation Calculator