Why should an early retiree use a lower withdrawal rate like 3.25–3.5% instead of 4%?

The 4% rule was tested on a 30-year retirement, but if you retire at 45 your money may need to last 45–55 years, and over that longer horizon a 4% start raises the odds of running out. Lowering the initial withdrawal to 3.25–3.5% sharply improves survival rates across historical and simulated outcomes because it leaves a bigger buffer for bad early markets and inflation. The trade-off is real: dropping from 4% to 3.5% raises your target from 25x to about 28.6x annual spending — roughly $1.7 million instead of $1.5 million on $60,000 of spending. Many early retirees split the difference: start near 3.5% and stay flexible, trimming spending in down years. The shorter your horizon, the closer to 4% you can run.