What rate of return should I assume when planning for the future?

Use conservative, realistic numbers rather than the headline historical average. U.S. stocks have returned roughly 10% annually before inflation over the long run, but planning on that invites disappointment. A safer approach is to plan in real (after-inflation) terms: many planners use about 5–7% real for a stock-heavy portfolio, or 4–5% real for a balanced 60/40 mix. Subtracting inflation (historically around 3%) keeps your projections honest about future purchasing power. For retirement income, the classic 4% safe-withdrawal guideline already bakes in conservative return assumptions. The danger of assuming high returns is undersaving — if you bank on 10% and get 6%, you arrive short. Better to plan low, save more, and be pleasantly surprised. Run your numbers with a few different return assumptions to see how sensitive your plan is. Stress-test scenarios at wealthserene.com/tools/wealth-simulator.