Barista FIRE Calculator (part-time income)

Understanding the Barista FIRE calculator — concept and principle

Barista FIRE is a version of financial independence where you leave full-time work early but keep a part-time job that covers some of your spending. Because your investments only have to fund the rest, the target portfolio is much smaller than for full FIRE. This calculator finds that target, the saving versus full FIRE, and how many years of saving it takes to get there.

Part-time income of $15,000 cuts the needed portfolio from $1,000,000 to $625,000.

How it is calculated

Portfolio needed = (annual spending − part-time income) ÷ safe withdrawal rate
Full FIRE target = annual spending ÷ withdrawal rate
Saving vs full FIRE = full target − Barista target = part-time income ÷ withdrawal rate
Years to Barista FIRE: each year, balance = balance × (1 + real return) + yearly saving, counted until the balance reaches the target (end-of-year contributions, capped at 100 years).

Use real (after-inflation) returns so that all figures are in today's money.

The principle

A withdrawal rate turns a yearly spending need into a portfolio size: at 4%, each $1 of yearly spending needs $25 invested. The 4% figure comes from US historical studies, such as Bengen's 1994 analysis and the 1998 Trinity study, which looked at how long portfolios lasted over roughly 30-year retirements. Every dollar of income you still earn is a dollar the portfolio does not have to provide, so it removes 1 ÷ withdrawal rate dollars from the target. In the US a part-time job can also bring health insurance, hence the name.

Worked example

Spending $40,000, part-time income $15,000, withdrawal rate 4%.
Gap the portfolio must cover = 40,000 − 15,000 = $25,000.
Portfolio needed = 25,000 ÷ 0.04 = $625,000, versus 40,000 ÷ 0.04 = $1,000,000 for full FIRE.
Saving vs full FIRE = $375,000 (15,000 ÷ 0.04).
Start at $150,000, add $30,000 a year, grow at 5% real: after 10 years about $621,671, after 11 years about $682,755. So it takes 11 years.

How to read the result

The target is the portfolio at which, with your part-time income, spending is covered at your chosen withdrawal rate. A lower withdrawal rate such as 3.5% gives a safer, larger target. The years figure is sensitive to the return assumption; try 3–4% real as a cautious case. Also ask how long the part-time job will last.

Common mistakes

Using nominal returns with today's spending, which overstates progress.
Assuming part-time income will last for decades.
Forgetting taxes on withdrawals and on the part-time wage.
Leaving out health-care costs.

Keep in mind: Results assume a steady real return and a constant withdrawal rate. Real markets vary and early losses hurt most. This is an estimate, not financial advice.

Frequently asked questions

Is 4% a safe withdrawal rate?

It held up for most 30-year periods in US history, but longer retirements and different markets may call for 3–3.5%.

What is the difference between Barista FIRE and Coast FIRE?

Coast FIRE stops saving and lets investments grow untouched until a normal retirement age. Barista FIRE starts drawing on the portfolio now, with part-time income filling the gap.

Sources: Bengen, W. P. (1994). Determining Withdrawal Rates Using Historical Data. Journal of Financial Planning · Cooley, Hubbard & Walz (1998). Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable. AAII Journal

Checked 8 Nov 2026. Standard financial mathematics (time value of money). Estimates for information only — not financial advice.

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