The Net Enough Equation:
Why Your Freedom Number is Higher Than You Think

Discover why taxes, inflation, and fees inflate your Freedom Number by 25-35%. Learn the Net Enough Equation and calculate your real retirement target with 2026 data.

Money365.Market Team
12 min read

You've done the math. 25 times your annual expenses. That's the Freedom Number—the portfolio that generates enough passive income to fund your lifestyle indefinitely. At $80,000 in annual expenses, you need $2,000,000. Simple. Except it's not. That $2,000,000 portfolio does not deliver $2,000,000 in purchasing power. Welcome to the world of wealth attrition—the invisible forces that erode your Freedom Number from paper to reality.

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KEY TAKEAWAY

The Net Enough Equation:
  • The original 4% rule was based on historical U.S. data—modern investors face different tax and fee landscapes
  • Three pillars of attrition: Tax Drag (15-20%), Inflation Gap (3% annually), Expense Ratios (0.5-1%)
  • A "gross" 4% withdrawal becomes approximately 2.4% "net"—a 40% effective reduction
  • The Net Enough Formula: Portfolio = Annual Expenses ÷ [(SWR - Fees) × (1 - Tax Rate)]
  • Your true Freedom Number is likely 25-35% higher than the standard 25x calculation suggests

The Trinity Study Revisited: Why 4% May No Longer Be Safe

In 1998, three professors at Trinity University published what would become the most influential retirement planning study in history. Their finding: a portfolio of 50% stocks and 50% bonds had a high probability of surviving 30 years with a 4% annual withdrawal rate. This "4% rule" became gospel.

But the Trinity Study was based on historical U.S. market returns from 1926-1995—a period that included the greatest bull market in history. It assumed no management fees, no platform costs, and—critically—no taxes on withdrawals. The original researchers examined portfolio survival, not purchasing power preservation. They asked "will the money last?" not "will the money buy the same goods in year 30 as it did in year 1?"

Modern research has adjusted the safe withdrawal rate downward. Morningstar's 2025 analysis suggests 3.7-4.0% for new retirees. Wade Pfau and other researchers recommend 3.25-3.5% for early retirees with 40+ year horizons. But even these updated rates ignore the three forces that transform your gross Freedom Number into something far smaller—as we discussed in Defining Your Enough, your target is only meaningful if it's anchored in reality.

The Three Pillars of Wealth Attrition

Pillar 1: Tax Drag—The 15-25% Silent Erosion

Tax drag refers to the portion of your investment returns lost to taxes. For retirees withdrawing from taxable accounts, this includes capital gains tax on appreciated assets and withholding tax on dividend income.

Most developed economies tax long-term capital gains at 15-20%. Dividend income from foreign stocks often faces withholding taxes of 15% at the source, with limited recovery options depending on your jurisdiction and account type. Even within tax-advantaged accounts, eventual withdrawals typically incur ordinary income tax.

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Tax Drag Impact on $100,000 Withdrawal

Gross withdrawal from taxable account: $100,000

Capital gains portion (assume 60%): $60,000

Tax at 15% capital gains rate: -$9,000

Dividend portion (40%): $40,000

Dividend tax at 15%: -$6,000

Net after tax: $85,000 (15% effective tax rate)

At 20% rates (higher earners), the same withdrawal yields only $80,000—a 20% reduction.

Pillar 2: The Inflation Gap—When 3% Compounds Against You

Nominal returns are what your brokerage statement shows. Real returns are what matters—your returns after subtracting inflation. The S&P 500 has delivered approximately 10% nominal returns historically, but real returns (after the long-term average ~3% inflation) are closer to 7%.

For retirees, this creates the Moving Goalpost Phenomenon: your $2,000,000 portfolio needs to grow just to maintain the same purchasing power. Every year, inflation pushes your real Freedom Number higher while eroding the value of fixed-income assets like bonds.

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The Moving Goalpost: Inflation Over 20 Years

Year 0 annual expenses: $80,000

At 3% annual inflation...

  • Year 10 equivalent: $107,500 needed for same lifestyle
  • Year 20 equivalent: $144,500 needed for same lifestyle

Your purchasing power erodes by 45% over 20 years at 3% inflation.

Pillar 3: Expense Ratios and Platform Fees—The Millionaire Maker (For Someone Else)

Investment fees compound against you with ruthless efficiency. The average actively managed fund charges 0.5-1.0% annually. Add brokerage platform fees, and a "typical" fee load reaches 0.75% cumulative. Over decades, this silent drain transfers staggering sums from your pocket to fund managers.

Fee Structure$1M After 30 YearsLost to Fees% Reduction
0.05% (Index Fund)$7,612,255$99,9291.3%
0.50% (Average)$6,614,367$997,81713.1%
1.00% (High Fee)$5,743,491$1,868,69324.5%

Source: Calculations assume 8% nominal return compounded annually. Based on ICI Fact Book 2024 fee data.

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"In investing, you get what you don't pay for. Costs matter. So do your returns."

John Bogle, Founder of Vanguard

The Net Enough Equation: Calculating Your True Freedom Number

The standard Freedom Number formula is elegant but incomplete:

Gross Freedom Number = Annual Expenses × 25

The Net Enough Equation adjusts for reality:

Net Freedom Number = Annual Expenses ÷ [(SWR - Fee Rate) × (1 - Effective Tax Rate)]

Where SWR is the Safe Withdrawal Rate (3.5-4%), Fee Rate is your cumulative expense ratio, and Effective Tax Rate is your blended rate on withdrawals.

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The Attrition Table: Three Investor Profiles

ProfileTaxFeesSWRNet SWRFreedom # ($80K)
The Naive Investor0%0%4.0%4.0%$2,000,000
The Realistic Investor15%0.2%3.5%2.8%$2,857,143
The High-Fee Investor20%1.0%3.5%2.0%$4,000,000

Formula: Net SWR = (SWR - Fees) × (1 - Tax Rate). Freedom Number = Annual Expenses ÷ Net SWR.

The Realistic Investor needs 43% more than the Naive Investor. The High-Fee Investor needs double. Same $80,000 lifestyle—wildly different requirements.

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The Waterfall of Attrition: Where Your Money Actually Goes

Imagine a $100,000 gross withdrawal cascading through the three pillars of attrition:

StageAmountErosion
1. Gross Withdrawal$100,000
2. After Capital Gains Tax (15%)$91,000-$9,000
3. After Dividend Tax (15%)$85,000-$6,000
4. After Platform Fees (0.25%)$84,750-$250
5. Real Purchasing Power (Year 1)$84,750-15.3%
6. Real Purchasing Power (Year 20, 3% inflation)$46,900-53.1%

Note: Tax calculations assume 60% capital gains, 40% dividend income. Inflation impact shows cumulative erosion.

Your $100,000 "withdrawal" becomes less than $47,000 in real purchasing power by year 20. This is why the naive 25x calculation is dangerously optimistic.

Strategies to Minimize Wealth Attrition

1. Optimize Asset Location

Asset location means placing investments in the right account types to minimize tax drag. Tax-inefficient assets (REITs, bonds, high-dividend stocks) belong in tax-advantaged accounts. Tax-efficient assets (growth stocks, index funds with low turnover) thrive in taxable accounts.

2. Choose Low-Cost Index Funds

The difference between a 0.05% and a 1.0% expense ratio represents nearly $1.8 million over 30 years on a $1 million portfolio. This isn't optimization—it's a non-negotiable. Total market index funds from major providers now charge 0.03-0.10%.

3. Implement Tax-Loss Harvesting

Tax-loss harvesting involves selling investments at a loss to offset capital gains, reducing your taxable income. When done systematically, this can add 0.5-1.0% annually to after-tax returns.

4. Plan Withdrawal Sequencing

The order in which you tap different accounts matters. A common strategy: withdraw from taxable accounts first (with tax-loss harvesting), then tax-deferred accounts, then tax-free accounts last. Roth conversion ladders can further optimize by converting tax-deferred funds at low tax rates.

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KEY TAKEAWAY

Asset Location Priority:
  • Tax-advantaged accounts: Bonds, REITs, high-yield dividends, actively traded funds
  • Taxable accounts: Total market index funds, growth stocks, tax-managed funds

The Freedom Audit: Recalculating Your Number

Use this checklist to convert your gross Freedom Number into a realistic net target:

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The Freedom Audit Checklist

  1. Calculate your true annual expenses—including healthcare costs that often inflate at 5-6% annually, not the general 3% rate
  2. Determine your blended tax rate—estimate the effective rate on your withdrawals based on account types and local tax jurisdiction
  3. Audit your investment fees—sum fund expense ratios, advisor fees, and platform costs
  4. Choose your safe withdrawal rate—3.5% for 30-year horizons, 3.25% for 40+ years
  5. Apply the Net Enough Equation—and accept that your target is likely 25-35% higher than the naive calculation

The Bottom Line: Net Is the Only Number That Matters

The 25x Rule is a useful starting point, not a destination. Your real Freedom Number must account for the three pillars of wealth attrition: tax drag, the inflation gap, and expense ratios. Ignoring these forces doesn't make them disappear—it just delays the moment when you realize your portfolio can't support your lifestyle.

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"In this world, nothing can be said to be certain, except death and taxes."

Benjamin Franklin

The Net Enough Equation transforms retirement planning from hopeful mathematics to realistic strategy. Calculate your gross number, apply the attrition factors, and build toward the target that actually matters: the one that delivers purchasing power, not just paper wealth.

Your future self—the one withdrawing 4% expecting $80,000 and receiving $47,000 in real purchasing power—will thank you for running the numbers that matter today.

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Investment Disclaimer

This article is for educational and informational purposes only and should not be construed as financial, investment, or professional advice. The content provided is based on publicly available information and the author's research and opinions. Money365.Market does not provide personalized investment advice or recommendations. Before making any investment decisions, please consult with a qualified financial advisor who understands your individual circumstances, risk tolerance, and financial goals. Past performance is not indicative of future results. All investments carry risk, including the potential loss of principal.

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