04/18/2026
Understanding the 4% Rule — How to Know If You Have Enough to Retire:
How do you know when you have enough money to retire?
Most people have no idea. They just hope. The 4% Rule gives you a concrete, research-backed answer.
WHAT IS THE 4% RULE?
Research from William Bengen (1994) and the Trinity Study found that a retiree can withdraw 4% of their portfolio in year one of retirement, then adjust for inflation each year — and have a very high probability of their money lasting 30+ years.
THE FORMULA:
Annual retirement expenses ÷ 0.04 = The portfolio you need to retire
EXAMPLES:
Need $40,000/year in retirement → You need $1,000,000
Need $60,000/year → You need $1,500,000
Need $80,000/year → You need $2,000,000
Need $100,000/year → You need $2,500,000
This is called your Financial Independence Number — the exact portfolio size at which your investments can fund your lifestyle indefinitely.
IMPORTANT CAVEATS:
1. The 4% rule assumes a diversified portfolio and a 30-year retirement. If you retire early, you may want to use 3-3.5% to be more conservative.
2. Social Security income reduces how much you need from your portfolio. Factor it in.
3. Taxes matter. If all your money is in pre-tax accounts, your 4% withdrawal is taxable. Tax-free sources (Roth IRA, IUL loans) dramatically improve your outcome.
4. Healthcare costs are often underestimated. Build in a healthcare buffer.
5. Inflation erodes purchasing power over time. Your portfolio needs to keep growing even in retirement.
THE CONNECTION TO FINANCIAL INDEPENDENCE:
The 4% Rule is the foundation of the FIRE movement (Financial Independence, Retire Early). You do not need a pension or Social Security to retire — you need a portfolio large enough that 4% of it covers your annual expenses.
What is your Financial Independence Number?