Coast FIRE Calculator

Coast FIRE is the point where your current retirement savings, left to grow untouched at your expected return, will compound into your full retirement number by your target retirement age without any more contributions. Once you reach it, you can "coast" — keep working or not, but stop adding to retirement and still retire on time.

First, your desired annual retirement spending is divided by a safe withdrawal rate (commonly 4%) to get your FIRE number — the full nest egg you need. That FIRE number is then discounted back to today at your expected annual return over your years until retirement, which gives the amount you'd need invested right now to coast.

A common planning assumption for a diversified stock-heavy portfolio is 6% to 8% annually after inflation. Using a lower return is more conservative and raises your coast number; a higher return lowers it but assumes more risk. Try a few different rates in the calculator to see how sensitive your result is.

No. Full FIRE (Financial Independence, Retire Early) means you already have enough invested to retire and live off withdrawals now. Coast FIRE means your current savings will grow into that number LATER, by your target retirement age, without more contributions — you're not retiring yet, just no longer required to save for retirement.

The calculator shows both your gap today and, if you enter a monthly contribution, the specific age you're projected to reach Coast FIRE by continuing at that pace. Contributing more, extending your timeline, or accepting a higher (riskier) expected return all move that date earlier.

Not as a separate input, but you can approximate it. Look up your estimated benefit with the Social Security Administration's tools, then subtract your expected annual Social Security or pension income from the "desired annual spend" figure you enter — that leaves only the portion your investments actually need to cover, since Social Security and a pension both supplement your portfolio rather than compete with it.

Yes, the same way as Social Security: subtract your expected net rental income (after expenses) from your desired annual spend, since that income covers part of your retirement need without your portfolio. Keep real estate equity itself out of the "current savings" field unless you'd actually sell and reinvest it, since this calculator projects liquid, invested assets compounding at a market return, not property appreciation.

Only through your spending goal, not as a separate input. If your mortgage will be paid off before you retire, don't include the payment in your "desired annual spend" — only your post-mortgage living costs. If you'll still be paying it in retirement, include that payment in your spending goal so the calculator solves for a portfolio big enough to cover it.

This page's calculator does the same math a spreadsheet would — projecting your current savings forward and discounting your retirement number back to today — without needing a download or a Google account. The formula behind it is straightforward: divide desired annual spending by your withdrawal rate for the FIRE number, then divide that by (1 + expected return) raised to your years until retirement for the coast number, so you're welcome to rebuild it in your own spreadsheet if you prefer to track it that way.

Yes — the calculator's growth math is pre-tax, so where your coast number sits changes what it's worth in retirement. A traditional 401(k) or IRA grows tax-deferred. But withdrawals count as ordinary income, so you'll owe tax before you can spend it. A Roth account grows tax-free. Qualified withdrawals owe no tax at all, so a Roth balance keeps its full value. A taxable brokerage account — the kind our investment calculator projects — owes capital gains tax on growth when you sell. Long-term capital gains are usually taxed at a lower rate than ordinary income. If most coast-number dollars sit in a traditional account, plan for a higher real number than the calculator shows. That gives your after-tax spending enough room to hit your actual goal.

Use a real, inflation-adjusted return, not a nominal one, if your spend goal is in today's dollars. The calculator's expected-return field is just one growth rate; it doesn't separate market growth from inflation. The long-run nominal average often quoted for the S&P 500 is close to 10% a year. A real return subtracts inflation's effect, showing what your money actually gains in buying power. Federal Reserve research puts the long-run historical real return on U.S. stocks at about 6.5% a year. Entering a 10% nominal return with a spend goal in today's dollars overstates how close you are to coasting. It ignores that future dollars will buy less. A real return like 6% to 7% keeps your coast number honest instead. It already accounts for inflation eating into your purchasing power over time.