What is the safe withdrawal rate?

The safe withdrawal rate (SWR) is the percentage of your retirement portfolio you can withdraw annually with a high probability of not running out of money over a 30-year retirement. The widely cited 4% rule comes from the Trinity Study. At 4%, a $1,000,000 portfolio generates $40,000/year. Retiring early (40s or 50s) may require a lower rate (3–3.5%) due to a longer retirement horizon.