What is the difference between fixed-percentage and inflation-adjusted withdrawals for an early retiree?

An inflation-adjusted (or 'constant dollar') withdrawal takes a set percentage in year one, then raises that dollar amount by inflation every year regardless of markets, which is what the classic 4% rule describes. Your income is smooth and predictable, but a bad early market can drain the portfolio because you keep spending the same real amount. A fixed-percentage withdrawal instead takes the same percent of your current balance each year, so you can never fully run out, but your income swings with the market and can drop sharply after a crash. Many early retirees blend the two: a percentage-of-portfolio floor with spending guardrails so income moves with markets but not violently. Which fits you depends on how much of your spending is essential versus discretionary. Model both at wealthserene.com/tools/fire-calculator.