100 Minus Age Asset Allocation Calculator
Age-based stock vs bond allocation.
Calculate stock-vs-bond allocation using the 100-minus-age rule of thumb — see the suggested percentage split for any age you put in.
What this tool does
A simple age-based asset allocation rule: subtract your age from 100 to get a suggested stocks percentage, with the remainder in bonds. The calculator shows how this formula distributes your portfolio between equities and fixed income based on age alone. The result represents a theoretical allocation model—useful for understanding how a basic rule of thumb works across different life stages. Age is the only input; the calculation doesn't account for individual risk tolerance, existing investments, income stability, or market conditions. This tool illustrates one approach to shifting from growth-oriented to conservative allocations as you move through different decades. The output is for educational exploration, not a personalised recommendation. Actual portfolio decisions involve many factors beyond age, and a full financial picture covers more than this rule captures.
Quick answer: with the default values, the result is 65.00% (Stock Allocation). Adjust the values below for your own figures.
Enter Values
People also use
Investing
Compound Interest Calculator
Free compound interest calculator with deposits, escalation, after-tax and inflation-adjusted projections, time-to-double, and sortable breakdown.
Investing
FIRE Number Calculator
Calculate your FIRE number using the 4% safe-withdrawal rule from annual retirement expenses, plus the gap to current savings and time to bridge it.
Investing
Asset Allocation Calculator
Calculate suggested portfolio asset allocation by age and risk tolerance (stocks/bonds/cash). Enter risk tolerance 1-10 to see suggested stock and bond.
Formula Used
Disclaimer
Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.
Classic '100 minus age' rule: stock allocation = 100 - age. 30 years old = 70% stocks, 30% bonds. 60 years old = 40% stocks, 60% bonds. Modern variants use 110 or 120 minus age for higher equity exposure.
Quick example
With your age of 35, the result is 65.00%.
What's happening under the hood
Stock % = 100 - age. Remainder in bonds.
Where this fits in planning
This is a "what-if" tool, not a forecast. It helps to test ideas: what happens to the result as you enter different ages. The value is in the scenarios you run, not the single answer you get from the defaults.
Where to go next
This calculation rarely sits alone in a planning exercise. If you're running these numbers, related tools include the compound interest calculator, the fire calculator, and the asset allocation calculator — each one answers a different question in the same territory.
Worked example
Suppose you are 45 years old. The formula gives 100 − 45 = 55. This means 55% stocks and 45% bonds. If your portfolio is worth 200,000 in your currency, the allocation becomes 110,000 in stocks and 90,000 in bonds. If you return to the calculator at age 50, the allocation shifts to 50% stocks and 50% bonds on the same portfolio size, which would mean shifting a total of 10,000 from stocks into bonds over those five years to keep pace with the changing rule.
Common situations where this rule appears
- Early-stage retirement planning when a simple starting point is more useful than no starting point
- Discussions about how asset allocation typically evolves across decades
- Educational contexts explaining the relationship between age and risk exposure
- Baseline comparison when evaluating a personalised or professionally designed allocation
What the result shows and does not show
The calculator shows how a single variable—age—produces a theoretical split between two broad asset classes. It does not account for income stability, existing assets, time horizon for specific goals, market conditions, tax environment, or personal risk tolerance. The output is for educational illustration and models one algorithmic approach to a complex decision.
At age 35 years, an age-based allocation strategy suggests 65.00% split between stocks and bonds.
Inputs
| Bond Allocation | 35.00% |
|---|---|
| Age | 35 |
| Modern Variant (110) | 75.00% |
| Aggressive (120) | 85.00% |
This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.
Sources & Methodology
Methodology
The calculator applies a simple age-based allocation model by subtracting your age from 100 to determine the percentage allocated to stocks, with the remaining percentage allocated to bonds. This approach assumes a linear reduction in stock exposure as age increases, treating equity allocation as inversely correlated with years to retirement. The model does not account for fees, taxes, inflation, individual risk tolerance, market volatility, or sequence-of-returns risk. It also does not model rebalancing frequency, asset class correlations, or time-varying returns. Results represent a static allocation snapshot based solely on age and do not reflect actual portfolio performance or suitability for any specific investor.
References
Frequently Asked Questions
Is this still valid?
What about my risk tolerance?
Bonds in retirement?
What about cash?
Related Calculators
Compound Interest Calculator
Free compound interest calculator with deposits, escalation, after-tax and inflation-adjusted projections, time-to-double, and sortable breakdown.
FIRE Number Calculator
Calculate your FIRE number using the 4% safe-withdrawal rule from annual retirement expenses, plus the gap to current savings and time to bridge it.
Asset Allocation Calculator
Calculate suggested portfolio asset allocation by age and risk tolerance (stocks/bonds/cash). Enter risk tolerance 1-10 to see suggested stock and bond.
More Investing Calculators
Investing
Active vs Passive Investing Calculator
Compare active versus passive investing over the long run. See how a percentage point of extra fees compounds into a wealth gap over decades.
Investing
Annuity Present Value Calculator
Calculate the present value of an ordinary annuity from regular payments, periodic rate, and the number of periods until the stream ends.
Investing
APR to APY Calculator
Convert APR to APY for any compounding frequency to see the true effective annual yield — what you actually earn (or pay) on a given quoted rate.
Investing
Asset Allocation Calculator
Calculate suggested portfolio asset allocation by age and risk tolerance (stocks/bonds/cash). Enter risk tolerance 1-10 to see suggested stock and bond.
Investing
Asset Allocation Drift Calculator
Calculate drift between current and target asset allocation to decide if rebalancing is needed. Enter equity to see drift percentage and rebalance flag.
Investing
Asset Allocation Return Calculator
Calculate weighted average return of a portfolio across equity, bond, and cash allocations. Enter equity return to see weighted portfolio return.
Explore Other Financial Tools
Debt
Overdraft Annual Cost Calculator
Estimate annual overdraft cost from average balance, days in overdraft, APR, and account fees. Returns interest, fees, and total annual cost.
Creator Economy
Blog Advertising Revenue Calculator
Calculate blog advertising revenue from pageviews and CPM rate, across different ad networks and ads-per-page densities.
Income
Depreciation Calculator
Calculate straight-line depreciation with annual and monthly amounts from asset cost, salvage value, and useful life in years.
Spotted something off?
Calculations or display — let us know.