When can I retire?Let’s run the numbers.

There is no single number. It depends on what you spend, when you stop working, what other income arrives and when, and how markets behave in the first decade after you retire. This calculator works the question backwards: you give it your spending, investments, contributions and Social Security estimate, and it reports how many historical retirements that plan survived and what level of spending those historical returns could support.

The 4% rule came from US historical data and a 30-year retirement, so it is a starting point rather than a guarantee. This model does not apply a fixed rate. It withdraws the spending you entered, adjusts it for inflation every year, and reports both the share of historical retirements the portfolio survived and the sustainable spending that history supports for the asset mix you picked.

Two retirements with the same average return can end very differently depending on when the bad years arrive. Withdrawals taken during a decline sell more shares and leave less invested to recover, so an early crash does lasting damage that a late one does not. That is why this calculator replays overlapping windows of real market history from 1926 onward instead of applying one average return. Every window has to cover your whole plan with complete data, so how far forward the start dates reach depends on your horizon, and the result names the first and last it tested.

No. Monte Carlo draws random returns from an assumed distribution. This model replays actual month-by-month US market history across every overlapping retirement window the record is long enough to cover, so each result is a sequence markets really produced. Those windows share most of their history, which means they are not independent trials, and the page says so with the result.

Yes. You enter the annual benefit from your ssa.gov statement and the age you plan to claim it. The model treats that benefit as inflation-indexed income starting at that age and uses it to reduce the withdrawal from your portfolio. Any years between retiring and claiming are funded by the portfolio alone.

Taxes, account types, required minimum distributions and Roth conversions are not modeled. Neither are fund fees, health insurance before Medicare, one-off expenses, changes in spending through retirement, home equity, or pensions other than the income you enter. Your asset mix is one of three presets rather than your real holdings. These limits are listed with your result.

The calculator is free and shows your result right on the page, with no account needed. To add what its six numbers leave out, like a pension, a partner, taxes, and health coverage, enter your email and choose a password, and your run opens in Ask Linc. There is no code to enter and no credit card.