Pension Calculator

def pension_projection(
    current_age: int,
    retirement_age: int,
    current_savings: float,
    monthly_contribution: float,
    annual_return_pct: float,
    inflation_pct: float,
) -> dict:
    """Project pension savings and retirement income."""
    years = retirement_age - current_age
    monthly_rate = annual_return_pct / 100 / 12
    months = years * 12

    # Future value of current savings (compound growth)
    fv_savings = current_savings * (1 + annual_return_pct / 100) ** years

    # Future value of monthly contributions (annuity formula)
    if monthly_rate > 0:
        fv_contributions = monthly_contribution * (
            ((1 + monthly_rate) ** months - 1) / monthly_rate
        )
    else:
        fv_contributions = monthly_contribution * months

    total_savings = fv_savings + fv_contributions

    # Monthly retirement income using the 4% rule
    annual_income = total_savings * 0.04
    monthly_income = annual_income / 12

    # Inflation adjustment (today's dollars)
    inflation_factor = (1 + inflation_pct / 100) ** years
    real_total = total_savings / inflation_factor
    real_monthly_income = monthly_income / inflation_factor

    return {
        "total_savings": round(total_savings, 2),
        "monthly_income_nominal": round(monthly_income, 2),
        "total_savings_real": round(real_total, 2),
        "monthly_income_real": round(real_monthly_income, 2),
        "years_to_retirement": years,
    }

result = pension_projection(
    current_age=35,
    retirement_age=65,
    current_savings=50_000,
    monthly_contribution=500,
    annual_return_pct=7.0,
    inflation_pct=3.0,
)
for key, value in result.items():
    print(f"{key}: {value:,.2f}" if isinstance(value, float) else f"{key}: {value}")