Asset Allocation Calculator

Investment asset allocation distributes a portfolio across asset classes — stocks, bonds, cash, real estate, and alternatives — to balance expected return against risk tolerance. Age-based allocation is the most common starting framework, reflecting the principle that younger investors can tolerate more volatility because they have more time to recover from market downturns.

Classic age-based equity allocation formula: Stock % = 110 − Age (traditional rule) Stock % = 120 − Age (modern rule, accounting for longer life expectancy)

Bond/fixed income allocation: Bond % = 100 − Stock %

Three-fund portfolio allocation example:

• US Total Stock Market: Stock % × 0.60
• International Stock: Stock % × 0.40
• Total Bond Market: Bond %

Where:

• Age: your current age in years
• Stock %: percentage of portfolio in equities (higher risk, higher expected return)
• Bond %: percentage in fixed income (lower risk, lower return, stability/income focus)

Risk-adjusted allocation modifiers:

• Add 5–10% to bonds if you are risk-averse or near a major financial goal
• Subtract 5–10% from bonds if you have high risk tolerance or very long horizon
• Emergency fund (3–6 months expenses) should be kept in cash, separate from investment portfolio

Historical average returns by asset class (US, 1928–2023):

• US Large-cap stocks (S&P 500): ~10.2% nominal, ~7.2% real
• US Bonds (10-year Treasury): ~4.6% nominal, ~1.7% real
• Cash (T-bills): ~3.3% nominal, ~0.4% real

Worked example: A 35-year-old investor using the 120-rule with moderate risk tolerance:

• Stock allocation: 120 − 35 = 85%
• Bond allocation: 15%
• Portfolio value: $150,000

Portfolio breakdown:

• US stocks: $150,000 × 0.85 × 0.60 = $76,500
• International stocks: $150,000 × 0.85 × 0.40 = $51,000
• Bonds: $150,000 × 0.15 = $22,500

At 55 (20 years later) using same rule: 120 − 55 = 65% stocks / 35% bonds.