Plan · Portfolio concentration
Portfolio Concentration Calculator
Enter holding values to see portfolio weights and top-three concentration. Add your own target weights to check allocation drift.
Scenario inputs
Change the assumptions.
- Holding A current value
- Holding B current value
- Holding C current value
- Holding D current value
Open the interactive calculator to enter values. Calculations run in your browser. Editing inputs does not change the page URL. Share calculation includes your inputs after # in the shared link. This URL fragment is not sent in the page HTTP request. Anyone with the link can read its values. Avoid sharing sensitive financial information.
How it works
Portfolio weight and allocation drift formulas
Holding weight (%) = current holding value ÷ total entered value × 100. Top-three concentration is the sum of the three largest weights, or all funded holdings if fewer than three are entered. Drift (percentage points) = current weight − your target weight. For example, $5,000 in a $10,000 portfolio is a 50% weight. Against a 40% target, drift is +10 percentage points, not a 10% investment return. Targets must total 100%; they are never silently normalized. Values and targets are rounded to two decimal places. Use current market values in one currency and combine duplicate positions before entering them.
Educational calculation only, not financial advice. Equity Replay is a historical simulator, not a broker or a record of trades. This snapshot is not a risk score, a forecast, or an instruction to rebalance. ETFs are counted as positions; their underlying holdings, sector exposure, and correlations are not analyzed.
Common questions
Before you use the number.
What does portfolio concentration measure here?
It measures how much of the entered portfolio value sits in its largest position and its three largest positions. It does not determine whether the portfolio is safe or suitably diversified.
How is portfolio drift calculated?
Subtract your target weight from the current weight. A 50% current weight against a 40% target is +10 percentage points. Negative drift means below your entered target. The tool does not choose targets or recommend trades.
Do I need target weights?
No. Concentration and current weights work without them. Enable target comparison only if you have your own targets; enter every target and make the total 100%.
Does this detect ETF overlap?
No. A fund is one entered position. Owning a fund and a direct stock can create underlying overlap that these totals cannot detect. Review fund holdings separately.
Can I enter cash or the same holding in several accounts?
Yes. Include cash if it belongs in the allocation you are measuring. Combine the same holding across accounts into one row. Use the same currency and valuation date for every row. The limit is 20 holdings; omitted positions change the denominator and results.
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