Safe Withdrawal Rate Calculator

The Trinity Study found that a 4% initial withdrawal rate from a stock-heavy portfolio survived every historical 30-year retirement window in US data from 1926 onward. Enter your numbers; we'll compute the income that rate produces and project the portfolio forward year by year at the real return (nominal return minus inflation) you specify.

Your plan

Portfolio value ($)

Withdrawal rate (%)

4% is the Trinity Study default; 3.5% is more conservative.

Inflation (%)

US long-run average is ~3%.

Expected return (%, nominal)

Real return = 4.0% (return minus inflation)

Retirement length (years)

Trinity Study uses 30; FIRE planners often use 40–50.

Annual income

$40,000

in today's dollars, adjusted upward each year for inflation

Monthly income

$3,333.33

Real return

4.0%

Horizon

30 years

Deterministic projection

Portfolio survives all 30 years

At a 4.0% real return, your balance at the end is $1,000,000 in today's dollars. This assumes constant returns — a real portfolio fluctuates, so a sequence of bad early years can still deplete a plan that looks fine on paper.

Trinity Study reference (1926–2009 US data)

Percent of historical 30-year retirement windows where an inflation-adjusted withdrawal at the listed rate survived the full 30 years. Higher rates and bond-heavy mixes fail more often.

Stocks / Bonds	3%	4%	5%	6%	7%
100% stocks	100%	96%	80%	62%	55%
75/25	100%	100%	82%	60%	45%
50/50	100%	100%	73%	39%	22%
25/75	100%	87%	47%	13%	0%
100% bonds	84%	35%	18%	8%	4%

Source: Cooley, Hubbard, and Walz (2011), updating the 1998 Trinity Study with data through 2009. Read row by stock/bond mix, column by withdrawal rate. Numbers below 100% are the share of 30-year windows in which the portfolio survived.

Educational, not financial advice. The 4% Rule is a heuristic from a single dataset (US stocks and bonds, 1926–2009). It does not account for sequence-of-returns risk in real markets, asset-class drift outside the studied period, taxes, fees, or country-specific outcomes. The deterministic projection above assumes constant returns and is not a Monte Carlo simulation. Use the numbers as a starting point and stress-test with a real planner.