Retirement Needs Calculator

A common heuristic from the "Trinity Study" is the 4% rule: you can withdraw 4% of your portfolio in year one, adjusted for inflation thereafter, with high probability of lasting 30 years. So if you need $60,000/year from your portfolio, you need $60,000 ÷ 0.04 = $1.5 million. More conservative withdrawal rates (3.0%–3.5%) require larger portfolios but improve durability.

The 4% rule comes from research by William Bengen and the Trinity Study, based on US historical returns. Critics note it assumes a 60/40 portfolio, US-style returns, and 30-year horizons - if you retire early or expect lower future returns, 3%–3.5% may be safer. Recent updated work (Morningstar, Bengen himself) suggests modest revisions but the framework still holds for most retirees.

Required savings depends on age, target income, and current balance. A 30-year-old with no savings targeting $60,000/year retirement income at 65 needs to save roughly $700–$1,000/month at 7% returns. Starting at 40 instead, the required amount roughly doubles. Use the calculator with your specific numbers - small assumption changes have big impacts over decades.

A common range is 5%–7% real (inflation-adjusted) for a stock-heavy portfolio, dropping to 3%–5% as you shift to bonds in retirement. Use real returns and today's dollars throughout to keep planning consistent. Stress-test with conservative assumptions (e.g., 4% real return) to ensure your plan works in modest market conditions.