You wanna spend 50k per year and retire now let's say. So Total = $50,000 × (1.04³⁰ − 1) / 0.04 Total ≈ $50,000 × 56.085 ≈ $2.80 million If you were 60 and wanted to stop working now and spend 50k in purchase power over the next 30 years, you need 2.8m USD of course.