Investment Portfolio Calculator
Model your investment portfolio across multiple asset classes. See projected growth, risk metrics, and Sharpe ratio to optimize your asset allocation strategy.
Quick examples:
Used for Sharpe ratio calculation (e.g., 10-year Treasury yield)
Portfolio Projection
Projected Portfolio Value
Expected Annual Return
Portfolio Risk
Total Contributions
Sharpe Ratio
Asset Allocation
Growth Over Time
(20 years)Related Calculators
How This Calculator Works
This investment portfolio calculator helps you model a multi-asset portfolio and project its growth over time. You define your asset allocation with expected returns and risk levels for each asset class, and the calculator computes key portfolio metrics including weighted return, portfolio risk, and the Sharpe ratio.
Weighted Portfolio Return
R_p = Σ(w_i × r_i)
The portfolio's expected return is the weighted average of each asset class's expected return, where the weights are the allocation percentages. For example, a portfolio with 60% stocks (10% return) and 40% bonds (4% return) has a weighted return of 7.6%.
Portfolio Risk
σ_p = √Σ(w_i² × σ_i²)
Portfolio risk is calculated as the square root of the weighted sum of squared individual risks. This simplified model assumes zero correlation between assets, demonstrating how diversification reduces overall portfolio volatility compared to holding a single asset.
Sharpe Ratio
Sharpe = (R_p - R_f) / σ_p
The Sharpe ratio measures risk-adjusted return by dividing the portfolio's excess return (above the risk-free rate) by its standard deviation. Higher values indicate better compensation for the risk taken. A ratio above 1.0 is generally considered good.
Portfolio Strategies
Conservative (Low Risk)
A conservative portfolio typically allocates 60-70% to bonds and 30-40% to stocks. This approach prioritizes capital preservation over growth, making it suitable for investors near retirement or those with low risk tolerance. Expected returns are lower but more predictable, typically in the 4-6% range.
Balanced (Moderate Risk)
A balanced portfolio splits roughly 50-60% stocks and 40-50% bonds, sometimes including 5-10% in alternatives like REITs. This offers a middle ground between growth and stability, suitable for investors with a 10-20 year horizon. Expected returns typically fall in the 6-8% range with moderate volatility.
Aggressive (High Risk)
An aggressive portfolio allocates 80-100% to equities, including international and small-cap stocks. This maximizes long-term growth potential but comes with significant short-term volatility. Best for young investors with a 20+ year horizon who can tolerate large drawdowns without selling. Expected returns are 8-12% but with wide annual variation.
All-Weather
An all-weather portfolio spreads investments across stocks, bonds, commodities, and real estate to perform reasonably well in any economic environment. Inspired by Ray Dalio's approach, it aims for consistent returns regardless of whether the economy is growing, contracting, or experiencing inflation. This strategy sacrifices peak returns for reduced drawdowns.
What This Calculator Assumes
To keep the results clear and actionable, this calculator makes several simplifying assumptions. Understanding these will help you interpret the projections correctly:
- •Constant returns: Each asset class earns its expected return consistently every year. In reality, returns vary significantly from year to year, which is why the risk metric is important for understanding potential volatility.
- •Zero correlation: The risk calculation assumes asset classes are uncorrelated. In practice, correlations exist and can change during market stress, potentially understating risk during severe downturns.
- •No rebalancing costs: The model assumes your portfolio maintains its target allocation without transaction costs or tax consequences from rebalancing.
- •No taxes, inflation, or fees: Results do not account for capital gains taxes, inflation erosion, or investment management fees, all of which reduce real returns.
- •Monthly compounding: Returns are compounded monthly using the portfolio's weighted average return. Monthly contributions are added at the end of each month.
Disclaimer: This tool provides estimates for educational and planning purposes. It is not financial advice. Past investment performance does not guarantee future results. For significant financial decisions, consider consulting with a qualified financial advisor who can account for your complete financial picture.
Frequently Asked Questions
What is portfolio diversification and why does it matter?
Portfolio diversification means spreading your investments across multiple asset classes such as stocks, bonds, real estate, and commodities. The goal is to reduce overall risk because different asset classes tend to perform differently under the same market conditions. When stocks decline, bonds often hold steady or rise, cushioning your portfolio. A well-diversified portfolio aims to achieve better risk-adjusted returns over time compared to concentrating all your money in a single asset class.
What is the Sharpe ratio and how should I interpret it?
The Sharpe ratio measures how much excess return you earn for each unit of risk you take. It is calculated as (portfolio return minus risk-free rate) divided by portfolio standard deviation. A Sharpe ratio above 1.0 is generally considered good, above 2.0 is very good, and above 3.0 is excellent. A negative Sharpe ratio means the portfolio returns less than the risk-free rate. Use the Sharpe ratio to compare different portfolio allocations and find the mix that gives you the best return per unit of risk.
What does portfolio risk (standard deviation) mean?
Standard deviation measures how much your portfolio returns are likely to vary from the average. A higher standard deviation means more volatility and wider swings in value. For example, a portfolio with 15% expected return and 20% standard deviation could reasonably return anywhere from -5% to +35% in a given year (one standard deviation range). Conservative investors typically aim for lower standard deviation, accepting lower returns in exchange for more predictable outcomes.
How should I allocate my portfolio based on my age?
A common rule of thumb is to subtract your age from 110 to determine your stock allocation. For example, a 30-year-old might hold 80% stocks and 20% bonds, while a 60-year-old might hold 50% stocks and 50% bonds. Younger investors can afford more risk because they have more time to recover from market downturns. As you approach retirement, gradually shifting toward bonds and other stable assets helps protect your accumulated wealth. This calculator lets you model different allocations to see how they affect your projected returns and risk.
What is the difference between expected return and actual return?
Expected return is the average annual return you anticipate based on historical data and market analysis. Actual return is what you really earn in any given year, which can be significantly higher or lower. Stock markets have historically averaged about 10% annually, but individual years have ranged from -37% to +54%. This calculator uses expected returns for long-term projections, which smooth out year-to-year volatility. Over long periods (20+ years), actual cumulative returns tend to converge toward historical averages, though this is not guaranteed.
How does rebalancing affect portfolio performance?
Rebalancing is the process of periodically adjusting your portfolio back to its target allocation. As different assets grow at different rates, your allocation drifts from the original targets. For example, if stocks outperform bonds, your portfolio may shift from 60/40 to 70/30, increasing your risk. Rebalancing forces you to sell high-performing assets and buy underperforming ones, which can improve long-term risk-adjusted returns. Most advisors recommend rebalancing annually or when any asset class drifts more than 5% from its target.
What rate of return should I expect from different asset classes?
Historical average annual returns vary significantly by asset class. US large-cap stocks have returned approximately 10% before inflation, small-cap stocks around 12%, international stocks about 8%, investment-grade bonds around 4-5%, real estate (REITs) about 8%, and cash equivalents around 2-3%. These are long-term averages and actual returns in any given period can differ substantially. For planning purposes, many advisors suggest using slightly conservative estimates below historical averages to build in a margin of safety.
Does this calculator account for correlations between asset classes?
This calculator uses a simplified risk model that assumes zero correlation between asset classes. In reality, asset classes have varying degrees of correlation. For example, US and international stocks are moderately correlated, while stocks and bonds tend to have low or negative correlation. The simplified model may slightly overestimate portfolio risk for well-diversified portfolios. For precise portfolio optimization that accounts for correlations, consider using tools that incorporate a full covariance matrix, or consult with a financial advisor.
How much should I invest each month?
A common guideline is to invest 15-20% of your gross income, including any employer retirement matches. However, the right amount depends on your financial goals, timeline, and other obligations. Start with whatever amount you can consistently afford, even if it is small. The power of compound returns means that starting early with smaller amounts often outperforms starting later with larger amounts. Use this calculator to model different monthly contribution levels and see how they affect your projected portfolio value over your chosen time horizon.
What is the risk-free rate and why does it matter?
The risk-free rate represents the return you can earn with virtually zero risk, typically measured by short-term government Treasury bills or the 10-year Treasury yield. It matters because it serves as the baseline for evaluating whether taking investment risk is worthwhile. If a portfolio returns 8% but the risk-free rate is 5%, your excess return for taking risk is only 3%. The Sharpe ratio uses the risk-free rate to measure this risk-reward tradeoff. As of recent years, the risk-free rate has been in the 4-5% range, though it fluctuates with monetary policy.