The question everyone asks, answered as far as arithmetic can.

Worked examples.

Five illustrations under stated assumptions. Every figure here is hypothetical; the tool is for the shape, not a forecast.

1. $1,500,000 at 62, spending $90,000 a year rising 3 percent with inflation and earning 5 percent, with no outside income, runs short at 81. The sustainable spending is about $59,528 a year.
2. The same plan with $40,000 a year of Social Security from 67 lasts through 95 with about $249,836 left; the sustainable spending rises to about $91,887.
3. Drop the return from 5 to 3 percent and the same plan runs short at 87. Two points of return over thirty years is the difference between a margin and a shortfall.
4. The first-year withdrawal rate is spending less outside income, over the balance. The old rule of thumb that 4 percent lasts thirty years came from historical sequences of real returns, which this calculator does not model; a fixed return flatters a plan.
5. Spending that falls with age, taxes on withdrawals, and a late long-term care bill all change the answer, and none is in the tool. It answers one narrow question well: at these assumptions, when does the money run out?

How the projection works.

Each year, spending rises with inflation; any outside income that has begun rises with it too; the difference is withdrawn from the portfolio; and what remains earns the return for the year. The first year the portfolio cannot cover the withdrawal is the year the money runs short. The sustainable spending is found by trying spending levels until the portfolio lands at zero in the last year of the horizon.

The picture is smooth because the return is the same every year. Real returns arrive in a sequence, and a poor sequence early in retirement, when withdrawals are taken from a shrinking balance, does more damage than the same returns in a different order. That is the single largest thing the tool leaves out, and the reason a plan that “lasts” here still deserves a margin.

Methodology and limits.

1. Inputs. The balance, spending in today's dollars, the current and planning ages, a nominal return, an inflation rate, and outside income with the age it starts.
2. The loop. Withdrawal = spending − income, both indexed from the first year; balance = (balance − withdrawal) × (1 + return). Nominal dollars throughout; the spending and income inputs are in today's dollars and are indexed forward.
3. Validation. With no return and no inflation, a balance of ten times spending runs out in exactly ten years; income equal to spending never runs short; the sustainable spending, re-run, lasts the horizon. A change to the loop that breaks any of these fails the build.
4. Not modeled. Sequence of returns, taxes on withdrawals, spending that changes with age, Medicare and long-term care costs, required minimum distributions, and the survivor's income after a death. Hypothetical; educational, not advice.

Revision history.

September 7, 2026

Added should you buy points (the bought-down loan against the plain one on the same principal and term, so the position is the interest saved less the cost of the points; true break-even as the first month at or above zero beside the simple rule; the horizon verdict; the return the points earn to the horizon as the monthly-compounded rate at which their cost equals the present value of the saving plus the lower balance owed, by bisection; the largest points count that pays off within the horizon; and the seller-paid case set against the same dollars off the price).

September 7, 2026

Added two mortgage assumption tools: refinance break-even (the simple rule, closing costs over the monthly saving, beside the month-by-month count of interest paid on each loan, where total cost is the balance plus the closing costs plus the interest so far, so the new loan's position is the interest saved less the costs; the reset-the-clock effect flagged when a longer term catches up), and 15-year or 30-year mortgage (the same cash on both paths, the 15-year payment invested after the loan is gone against the difference invested for thirty years, compared at year 15, year 30, and a chosen horizon, with the break-even return by bisection).

September 7, 2026

Added three assumption tools: Roth or traditional 401(k) (the same take-home cost grown at one return and taxed at each end, so the answer turns on the two rates; the plan limit from the annual record), pay off the mortgage or invest (two month-by-month paths, the extra to the mortgage and then the freed payment invested, against the extra invested throughout, with the optional interest deduction), and how much life insurance (the present value of the income to replace as a growing annuity, plus debts, final expenses, and education, less existing coverage and savings, beside the ten-times-income rule).

September 6, 2026

Added two assumption tools: sell or keep the house (carrying costs and appreciation against rent and the return on freed equity, with the home-sale exclusion), and the long-term care cost projection (today's rate at care inflation to the start year, summed over the years of care, with the set-aside today).

September 4, 2026

First release of the longevity projection (year-by-year, spending and outside income indexed to inflation, a fixed return on the remainder, with the sustainable-spending solver) and the pension-versus-lump-sum comparison (the lump sum invested and paying the pension, with the break-even return solver).

Canonical address: https://consideratecapital.com/tools/will-my-money-last