FIRE Calculator — United States

Most early retirement calculators grow your savings at a flat rate and stop at 25 times your spending. That skips the parts that change the answer by years: how 401(k) deferrals and FICA interact, what the employer match adds, and the fact that most retirement accounts charge a penalty before 59½. This calculator runs your paycheck through the 2026 federal rules every year until you retire, then draws the money down year by year to the age you plan to.

Your brokerage account grows at its own return, less fees and a tax drag for dividends taxed along the way. The 401(k) and IRA pool grows untaxed. Once you retire, spending comes from the brokerage account until 59½, then from both pools in proportion. The figures come from the IRS 2026 inflation adjustments and 2026 retirement plan limits; Assumptions & method lists every one. IRA balances belong in the 401(k) + IRA balance; the IRA limit is $7,500 in 2026.

Withdrawals from a 401(k) or IRA before 59½ generally carry a 10% additional tax on top of income tax (IRS). So if you stop work at 45, the 14½ years until 59½ have to be funded from money you can reach: a taxable brokerage account, cash, Roth IRA contributions, or part-time income. Those years are the bridge, and a plan with plenty in its 401(k) can still fail them.

The calculator tests the bridge directly. For every retirement age it tries, spending before 59½ can only come from the brokerage pool. If that runs out first, the age fails. The bridge panel shows how much you need outside retirement accounts, how much the projection has there, and the difference.

There are lawful ways to reach retirement money earlier: the Rule of 55, 72(t) substantially equal periodic payments, and a Roth conversion ladder (IRS exceptions). The calculator flags them in the bridge panel but does not assume you will use them, because each comes with conditions.

Your FIRE age is the earliest age at which the money lasts to your plan-to age, 95 by default, with every year's spending paid in full.

Today's dollars. Every balance is shown in today's purchasing power, so a balance decades away is shown as what it would buy now.

Fixed returns. The projection assumes the same return every year. That keeps the answer stable, but it hides sequence risk, a run of poor years early in retirement. Run the plan through the drawdown simulator to see a range of outcomes.

Taxes in retirement default to 8% of withdrawals: a blend of long-term capital gains on the brokerage account and ordinary income on traditional 401(k) withdrawals, after the standard deduction. Roth accounts are not modelled separately.

Social Security is left out unless you add it under Other income & expenses.

• Retirement spending. Each $1,000 a year you plan to spend needs roughly $25,000 more invested at 4%. Cutting spending now also frees more to invest, so it shortens the timeline from both directions.
• Your savings rate. The share of take-home pay you invest sets how fast the gap closes; the savings rate calculator shows it on its own.
• 401(k) or brokerage. Deferrals cut income tax now and grow untaxed, but they are locked until 59½ without an exception. Brokerage savings are taxed first but fund the bridge. The calculator shows both effects at once.
• The employer match. By default it adds 50% of your deferrals, up to 6% of pay. Deferring less than the match limit leaves part of it unpaid, which the projection reflects.
• Fees and returns. The defaults are 8% a year before fees, 0.1% in brokerage fees and 0.2% in the 401(k), with 2.5% inflation. Why the defaults are reasonable explains each one.