Stocks vs Bonds Asset Allocation Calculator

Recommended stock / bond / cash split by age and risk tolerance — age-in-bonds, "120-minus-age", and target-date glide-path conventions.

Inputs

Shorter horizons reduce equity allocation regardless of age.

Result

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General calculation reads

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How to use this calculator

  • Enter your current age.
  • Pick risk tolerance honestly — the one that lets you sleep through a 30%+ drawdown without selling.
  • Set horizon = years until you need to spend the money. For retirement at 65 and you're 35, that's 30+ years.
  • The recommended split is a starting point — adjust for your specific liabilities and tax situation.

About this calculator

Asset allocation matters more than security selection for long-run returns. The classic "age in bonds" rule (bonds % = your age) was the standard for decades but is now considered too conservative because Americans live longer — a 65-yo today has a 50% chance of living past 85 and a 25% chance past 95. The modern Bogle / Vanguard adjustment is "120 minus age" for stock allocation. Target-date funds at Vanguard, Fidelity, and Schwab follow a published glide path that starts around 90% stocks for someone 30 years from retirement and ramps down to ~30% stocks by age 75. Risk tolerance flexes the rule ±10-15 percentage points: conservative investors gravitate lower-equity than the age rule suggests; aggressive higher. Horizon overrides everything — if you need the money in 3 years, you cannot be 80% in stocks no matter your age.

Frequently asked

Why does "age in bonds" feel too conservative now?+
It was calibrated to a 25-30 year retirement horizon. With average US life expectancy at 79 and many retirees living past 90, a 65-yo today may need 30+ years of growth. Equity allocation appropriate for someone with 10 years left is too low for someone with 30.
Are international stocks really worth a 40% allocation?+
Industry consensus (Vanguard, BlackRock, Bogleheads wiki) is 30-40% international based on market-cap (US is ~60% of global equity-market value). Some commentators argue lower; 0% international is uncommon in modern portfolios.
What about TIPS / I-Bonds in the "bonds" slice?+
For investors near or in retirement, swapping 10-15% of nominal Treasuries for inflation-protected securities (TIPS, US I-Bonds up to the annual limit) hedges purchasing-power risk. This calc reports the total bond percent — internal split is left to the investor.
Should real estate count as "stocks" or "bonds"?+
REITs trade like stocks (high vol, high return); private real estate equity is its own category. For a household balance sheet, treat your primary residence separately (it provides utility, not market exposure) and REITs as part of equity.
Source for the Vanguard glide-path benchmark?+
Vanguard Target Retirement Fund prospectus (https://investor.vanguard.com/investment-products/list/target-retirement-funds). The cohort allocations cited here are the round-number midpoints from the publicly published glide-path graphic.
Source for "120 minus age" rule?+
Popularised by Jack Bogle in interviews + Boglehead community wiki; not from a formal Bogle publication but well-established industry rule of thumb. Also referenced in Vanguard's "Principles for Investing Success" 2024 edition.

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