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100 Minus Age Asset Allocation Calculator

Updated April 17, 2026 · Investing · Educational use only ·

Age-based stock vs bond allocation.

Calculate stock vs bond allocation using 100-minus-age rule. Shows stock and bond allocation percentages from the values you enter.

What this tool does

Enter your age. The tool shows stock and bond allocation percentages.


Enter Values

Formula Used
Current age

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Calculations, display, or translation — let us know.

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%. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.

What's happening under the hood

Stock % = 100 - age. Remainder in bonds. The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.

Where this fits in planning

This is a "what-if" tool, not a forecast. Use it to test ideas before committing: what happens if the rate is 2% lower than hoped, what happens if you add five more years. The value is in the scenarios you run, not the single answer you get from the defaults.

What this doesn't capture

Steady-rate math ignores real-world volatility. Actual returns are lumpy; sequence-of-returns risk matters most in drawdown; fees and taxes drag on compound growth; and behaviour changes in drawdowns can reduce outcomes below the projection. Treat the number as one scenario, not a forecast.

Where to go next

This calculation rarely sits alone in a planning exercise. If you're running these numbers, you'll probably also want the compound interest calculator, the fire calculator, and the asset allocation calculator — each one answers a different question in the same territory. Treating them as a set rather than in isolation usually produces a more honest picture.

Example Scenario

Age-based allocation produces split based on the inputs provided.

Inputs

Your Age:35 years
Expected Result65.00%

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

Stock % = 100 - age. Remainder in bonds.

Frequently Asked Questions

Is this still valid?
Rough guideline. Modern thinking favours higher equity (110 or 120 minus age) due to longer lifespans and lower bond returns.
What about my risk tolerance?
Critical adjustment. Conservative investors may use lower equity even when young. Aggressive investors higher. Rule is starting point only.
Bonds in retirement?
Traditional advice. Modern view: international diversification, dividend stocks, REITs offer alternative income with growth potential.
What about cash?
Not in this rule. Most planners suggest 1-3 years cash for emergencies/short-term needs separately.

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