FIRE Calculator with Pension 2026

Why pension holders have a different FIRE problem

The standard FIRE framework assumes your portfolio is the only income source in retirement. Spend $80,000 per year, multiply by 25, and you need a $2 million portfolio. That math applies to private sector workers who will draw Social Security at 67 and nothing else before then.

Teachers, police officers, firefighters, and federal employees are different. They often have a defined benefit pension that begins at retirement, or within a few years of it. A pension paying $2,500 per month is worth $30,000 per year in guaranteed income. Under the 4% rule, that pension replaces $750,000 in portfolio savings. A teacher who would need $2 million without a pension might only need $1.25 million with one.

Most FIRE calculators on the internet do not account for this. They ask for your spending and return a number that assumes you need the portfolio to cover everything. The result is that public employees with pensions drastically overestimate how much they need to save. Some delay retirement by years because of a number that was wrong from the start.

The 4% rule and its limits

William Bengen's 1994 research established the 4% rule by backtesting 50/50 stock and bond portfolios against every 30-year period from 1926 to 1963. The worst historical periods still survived a 4% initial withdrawal rate, adjusted annually for inflation. The subsequent Trinity Study (1998) extended this work and reached similar conclusions.

The rule has real limits. It was designed for 30-year retirements, not 40 or 50-year retirements. Early retirees at 45 or 50 are outside the original research window. A 3% or 3.5% withdrawal rate (33x spending as the target) provides significantly higher historical success rates for longer retirements. This calculator shows both the 4% number and the conservative 3% number so you can see the range.

The rule also assumes a specific asset allocation and consistent withdrawals. Real retirements are messier: spending varies, pensions provide partial coverage, and Social Security adds another income stream. The year-by-year table in the calculator models these changes explicitly, showing when pension and Social Security income changes your portfolio withdrawal requirement.

The bridge period problem

Many public employees face a gap between retirement and when their pension or Social Security starts, or both. A teacher who leaves at 55 might not receive her pension until 58 and cannot claim Social Security before 62. The three years from 55 to 58 require entirely portfolio-funded living. The five years from 55 to 60 require portfolio funding or reduced pension.

This bridge period is often the binding constraint on early retirement. A portfolio sufficient to sustain 4% withdrawals at full spending, for 30 years, might not survive a 5-year period where 100% of expenses come from savings before guaranteed income kicks in. The calculator models this bridge separately and shows how much portfolio you need to fund just the gap years.

The 457(b) account is especially useful here. Unlike the 403(b) or 401(k), the 457(b) carries no 10% early withdrawal penalty. A public school teacher with $200,000 in a 457(b) can draw it down during the bridge years paying only income tax. That flexibility is worth a significant amount to anyone retiring before 59.5.

Pension's dollar value: what it actually means

Financial planners talk about the "present value" of a pension stream, which is the lump sum that, invested today, would generate the same income. Under the 4% rule, a $1,000 monthly pension ($12,000/yr) has a portfolio equivalent of $300,000. You don't need to save that $300,000 because the pension provides it automatically.

This is why public sector pensions, often dismissed as old-fashioned, represent serious wealth. A teacher with a $3,000 monthly pension has the portfolio equivalent of $900,000. A 20-year firefighter with a $4,000 monthly pension has the equivalent of $1.2 million. These are large numbers. They are also numbers that don't appear on any brokerage statement, which is why people underestimate how close to FIRE they actually are.

The calculator shows this explicitly: your FIRE number without the pension, your FIRE number with it, and the difference. Most pension holders find the gap large enough to change their retirement timeline.

Social Security and the FIRE timeline

Claiming Social Security at 62 reduces the benefit by roughly 30% compared to claiming at full retirement age (67 for most people born after 1960). Waiting until 70 increases the benefit by 24% above the full retirement age amount. For early retirees who have stopped working at 50 or 55, the break-even calculation on Social Security is different than for someone retiring at 65: you have more years to live and the delayed credits compound longer.

Early retirement also means fewer years of earnings credits going into the Social Security calculation. The SSA averages your top 35 earning years; zeros for years you don't work count against you. This calculator uses your stated Social Security estimate from ssa.gov, which already accounts for your actual work history. Use the estimate for your projected claiming age, not the full retirement age estimate.

Sequence of returns risk for early retirees

The biggest risk in early retirement is not a low average return over 30 years. It is a severe market downturn in the first 5 to 10 years of retirement, before the portfolio recovers. A 40% loss at age 55, followed by strong returns, produces dramatically worse outcomes than a 40% loss at age 75. This is sequence-of-returns risk, and it hits early retirees hardest.

The conservative scenario in this calculator caps the return assumption at 5%. This is not a prediction; it is a stress test. If your plan still works at 5% returns, you have a meaningful cushion against a bad first decade. If it only works at 7% or 8%, you are counting on above-average performance from day one. Few early retirees can afford that assumption.

A pension reduces sequence-of-returns risk by providing a floor. If the portfolio drops 40%, you still have $2,500 per month from the pension to cover basic expenses. You can let the portfolio recover without being forced to sell at low prices to fund living costs. This is one of the underappreciated advantages of retiring with a defined benefit alongside an investment portfolio.