Free ToolNo signup required
Portfolio Calculator
Analyse your portfolio allocation, concentration, and weighted expected return.
How to Analyse Your Portfolio Allocation
Weight Calculation
Weight = Holding Value / Total Portfolio
Weighted Return = Sum(Weight x Return)
Each holding's weight is its share of total portfolio value. The weighted expected return combines each holding's return by its weight, giving a portfolio-level figure.
Concentration Index (HHI)
HHI = Sum(Weight^2)
< 1500 = Low | 1500-2500 = Med | > 2500 = High
The Herfindahl-Hirschman Index sums the squares of each holding's percentage weight. Lower values mean your money is less concentrated in any one holding — but concentration is not the same as diversification. True diversification depends on how holdings move together: measure that with the correlation and covariance calculators. An equally-weighted 10-holding portfolio scores 1,000.
Asset Allocation Guidelines
By Risk Tolerance
Conservative: 30% stocks, 50% bonds, 20% cash. Balanced: 60% stocks, 30% bonds, 10% alternatives. Aggressive: 80-90% stocks, 10-20% alternatives. Higher equity allocations offer greater long-term growth potential but with more short-term volatility.
By Life Stage
Early career (20s-30s): higher equity weighting, time to recover from downturns. Mid-career (40s-50s): gradually shift toward bonds and diversifiers. Pre-retirement (60s+): capital preservation focus with income-generating assets. Adjust based on personal circumstances and risk appetite.
How to Use This Portfolio Calculator
Add Your Holdings
Enter each holding with its current value, expected return, and asset class.
Analyse Allocation
See weights, asset class breakdown, and concentration score instantly.
Optimise & Rebalance
Adjust holdings to improve diversification and target returns.
Understanding Portfolio Metrics
- Portfolio Weight vs Equal Weight. Market-cap or value-weighted portfolios naturally concentrate in your largest positions. Equal-weighting gives every holding the same influence, which improves diversification but requires frequent rebalancing.
- Diversification vs Diworsification. Adding too many correlated assets (e.g. multiple UK equity funds) adds complexity without meaningful diversification. Focus on assets with low correlation to each other for genuine risk reduction.
- Expected Return Limitations. Expected returns are estimates, not guarantees. Historical averages: stocks ~8-10%, bonds ~3-5%, cash ~1-3%, property ~6-10%. Actual returns vary significantly year to year.
- Rebalancing Drag. Rebalancing involves selling winners and buying laggards. While this manages risk, transaction costs and capital gains tax can create a small drag on returns. Tax-efficient rebalancing directs new contributions to underweight assets instead.
Want true diversification, not just concentration?
This calculator measures concentration from the weights you enter — it cannot see how your holdings actually move together. For correlation-based diversification and an optimised portfolio, create a free ARIA account: build a portfolio by hand from a large universe of securities, enter your transactions, or import your broker transaction history. ARIA then computes the full correlation/covariance picture, risk-adjusted metrics, and an optimised allocation across your real holdings.
Create Free Account