4% Rule vs Trinity Study Update 2027 Calculator
The 4% rule is a rule of thumb for retirement income: withdraw 4% of the portfolio in the first year, then keep that amount level in real terms. This calculator shows the first-year and monthly withdrawal for the rate you choose, the total withdrawn over your retirement in today's dollars, and how long the money would last if investment returns only matched inflation. It does not estimate a probability of success.
How the 4% Rule Works
You take 4% of the starting portfolio in the first year — $80,000 from $2,000,000 — and in later years withdraw the same amount adjusted for inflation, regardless of how markets move. The idea comes from studies of historical US market returns over 30-year retirements, including the 1998 paper by Cooley, Hubbard and Walz known as the Trinity Study.
Why the Rate Matters
A lower rate leaves more room for poor returns and for longer retirements. At 3%, $2,000,000 gives $60,000 a year; at 5% it gives $100,000. If the portfolio earned nothing above inflation, 4% would last 25 years, 3% about 33 years and 5% only 20 years. Any longer retirement relies on real growth.
What This Calculator Does Not Do
It does not simulate markets, taxes, fees or the order in which good and bad years arrive, and it gives no probability that the money will last. Flexible approaches that cut spending after poor returns are also not modelled.
Source and Disclaimer
No statistics are built into this page; results come only from your inputs. It is not financial advice — past returns do not guarantee future ones.
Method: arithmetic on your own inputs; no historical return data or success rates are used. Last updated: October 2026.