Asset Allocation Calculator
Determine target stock/bond allocation using the 120-minus-age rule, adjusted for risk tolerance.
About this calculator
This calculator applies the "120 minus age" rule of thumb -- a widely cited heuristic for a starting stock allocation, not a regulatory or actuarial standard -- and then adjusts that baseline for Risk Tolerance: each step above or below "Moderate" on the five-point scale shifts the stock allocation by 10 percentage points, so a Very Aggressive investor lands 20 points higher and a Very Conservative investor lands 20 points lower than the age-only baseline, subject to a floor of 10% and a ceiling of 100% in stocks. Risk Tolerance is a single discrete choice that can swing the recommendation by up to 40 percentage points in one step change (moving from Very Conservative to Very Aggressive), which is a bigger single move than a small nudge in Age alone produces -- though Age still sets the entire baseline before any risk adjustment is applied, and matters enormously across its full range from 18 to 90. The resulting stock allocation is further split 70/30 between domestic and international equities, and the bond allocation 50/50 between government and corporate bonds -- fixed splits this calculator applies uniformly, not personalized sub-allocations.
Expected Return and Expected Volatility are simple weighted averages of assumed long-run stock and bond figures (10% return / 16% volatility for stocks, 4% return / 5% volatility for bonds), not a forecast or a guarantee -- actual market returns vary substantially and unpredictably from any historical average. The volatility figure in particular is a straight weighted average, not a true portfolio standard deviation: it ignores the correlation between stocks and bonds entirely, and because diversification generally reduces combined risk below the weighted average of its parts, this figure should be read as an upper bound on expected volatility rather than a precise estimate. This calculator drives the recommended split entirely from Age and Risk Tolerance.
Financial Disclaimer
This calculator is for educational purposes only and does not constitute financial advice. Results are estimates based on the inputs provided. Consult a qualified financial advisor before making investment or financial planning decisions.
Inputs
Results
Stock allocation (%)
85%
How to Use This Calculator
- Enter your current age and select your risk tolerance on a scale from conservative to aggressive.
- Input your current total investment portfolio value.
- Review the recommended Stock % and Bond % allocation based on age-adjusted and risk-adjusted formulas.
- Check Expected Return % to see the projected annual return for your recommended allocation.
- Use Expected Volatility % to understand the expected annual swings — higher volatility may be uncomfortable if you're risk-averse.
How the result changes with Your age
| Your age | Stock allocation (%) |
|---|---|
| 18 | 100% |
| 26 | 94% |
| 53 | 67% |
| 88 | 32% |
What each input means
- Your age
- Your current age.
- Risk tolerance
- Your comfort level with investment risk and volatility.
- Portfolio value ($)
- Current total investment portfolio value.
What each result means
- Stock allocation (%)
- Recommended percentage in equities.
- Bond allocation (%)
- Recommended percentage in bonds.
- Stock amount ($)
- Dollar amount to hold in stocks.
- Bond amount ($)
- Dollar amount to hold in bonds.
- Expected return (%)
- Weighted average expected annual return.
- Expected volatility (%)
- Weighted average annual standard deviation.
How this is calculated
Worked example, using the default values
- Identify Input Parameters3 parametersYour age = 35, Risk tolerance = 3, Portfolio value ($) = 100000 = 3 input(s) provided
- Calculate Stock allocationStock allocation85 = 85%
- Calculate Bond allocationBond allocation15 = 15%
- Calculate Stock amountStock amount85000 = $85,000
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why doesn't Portfolio Value affect Stock Allocation (%) or Bond Allocation (%)?
The percentage splits come from Age and Risk Tolerance alone and are the same whether the portfolio is worth $10,000 or $10 million. Portfolio Value only enters the calculation afterward, when converting those percentages into Stock Amount ($) and Bond Amount ($) -- the dollar figures scale directly with portfolio size even though the percentages do not.
How much does Risk Tolerance actually move the recommendation?
Each step on the five-point Risk Tolerance scale shifts the stock allocation by 10 percentage points relative to the age-based baseline -- Very Aggressive adds 20 points, Aggressive adds 10, Moderate adds none, Conservative subtracts 10, and Very Conservative subtracts 20 -- before the result is clamped between a 10% floor and a 100% ceiling in stocks.
Are Expected Return and Expected Volatility a prediction of future performance?
No -- they are a weighted average of assumed long-run figures for stocks and bonds applied to your specific allocation percentages, not a forecast. Real market returns and volatility vary substantially from any single historical assumption, and this calculator does not model economic cycles, sequence-of-returns risk, or asset classes beyond a simple stock/bond split. Expected Volatility specifically is a plain weighted average of the assumed stock and bond volatility figures, not a true portfolio standard deviation -- it does not account for the correlation between stocks and bonds. Because diversification generally reduces combined portfolio risk below the simple weighted average of its parts, treat this number as a rough upper bound rather than a precise risk estimate.
Why is the international stock split always 30% of the stock allocation?
This calculator applies a fixed 70/30 domestic-to-international split to whatever total stock percentage the age and risk-tolerance formula produces, rather than deriving that ratio from any input you control. Investors who want a different domestic/international mix would need to adjust their actual holdings independently of this calculator's sub-allocation figures.
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