Enter your age, savings, monthly contribution, expected return, and withdrawal rate to project your retirement nest egg and sustainable income.
How to Use the Retirement Calculator
Fill in your current age, planned retirement age, current savings, and monthly contribution, then set an expected annual return and a withdrawal rate. The nest egg projection, sustainable income, and contribution totals all recompute as you adjust any field.
The balance grows the same way a 401(k) does here — monthly compounding, contribution added every month — just without an employer match layered on top:
Balance(next month) = Balance × (1 + Monthly Return) + Monthly ContributionWhere the 4% Comes From
The withdrawal rate defaults to 4% because of a specific piece of research: financial planner William Bengen's 1994 study, later popularized and extended by Trinity University's "Trinity Study" in 1998, found that withdrawing 4% of a portfolio's starting value each year, adjusted for inflation, let a diversified stock-and-bond portfolio survive at least 30 years across nearly every historical rolling period examined. It became shorthand for "safe withdrawal rate," even though Bengen's own later work suggested the number could go somewhat higher or lower depending on the market environment at retirement.
What This Number Doesn't Account For
This is a rule of thumb built on past US market history, not a guarantee about the future — markets that performed a certain way from the 1920s through the 1990s aren't obligated to repeat. Two more gaps are worth naming directly: this calculator projects growth using one flat nominal return, with no inflation adjustment, so the dollar figures are today's dollars, not future purchasing power; and it doesn't model sequence-of-returns risk, the danger that a market downturn hitting right as you retire can deplete a portfolio much faster than the same average return spread evenly over decades. Both are real risks a full retirement plan needs to account for, and neither shows up in the number above.