FIRE Number by Flavor — Lean vs Regular vs Fat
Generic calculators multiply your spending by 25 and stop. That number silently assumes a 30-year retirement, one withdrawal rate for every budget, pre-cliff ACA subsidies, and Social Security that starts the day you quit. This one uses a flavor-specific withdrawal band (a lean budget has no slack to cut, so it gets the conservative band), adjusts the multiple for your horizon, itemizes the restored 2026 ACA 400% FPL cliff per flavor, and subtracts Social Security as a present value on the portfolio side.
Lean vs Regular vs Fat
low · typical · high per flavorLean — conservative band, no discretionary slack to cut in a drawdown:
Regular — just under the classic 4% anchor:
Fat — discretionary spending can flex down, so the band runs higher:
Coral = optimistic end (high withdrawal rate, full Social Security), green = typical, lime = conservative end (low rate, TIPS-30 discount, Trustees 77% payable haircut).
ACA line item, per flavor
2026 law · enhanced credit expired 2025-12-31| Flavor | MAGI vs FPL | Net premium | Status |
|---|---|---|---|
| Lean | — | — | — |
| Regular | — | — | — |
| Fat | — | — | — |
For 2026 the 400% FPL cliff is back: $1 of MAGI over the line forfeits the entire premium tax credit — typically a five-figure annual jump for a fat budget. Congress may still act retroactively; treat every subsidy figure as a projection contingent on legislation.
Formula correction — the PV(SS) bug
regular flavor, typical assumptionsThe shortcut nets Social Security out of spending as if the check starts the day you retire. It doesn't — the benefit's present value is subtracted from the portfolio side, and the years before claim age are a bridge you fund yourself.
Show the math ›
Assumptions & sources ›
| Assumption | Value | Source · asOf |
|---|---|---|
| Withdrawal band — lean | 3.25–3.5% (50-yr anchor) | Early Retirement Now, SWR Series — 60-yr historical failsafe at 75–100% equity · asOf 2026-07 · lean budgets get the conservative band: no discretionary room to cut |
| Withdrawal band — regular / fat | 3.7–4.0% / 4.0–4.25% | Bengen (1994), J. Financial Planning — SAFEMAX 4.15% at 30 yrs, 50/50 · asOf 2026-07 · fat's discretionary share can flex down in a bad sequence |
| Horizon adjustment | +0.5pp at 30 yrs … −0.2pp at 60 yrs | Bengen 30-yr vs ERN long-horizon spread (~0.7–0.9pp), interpolated · 25× is a 30-year multiple; 45-yr retirements land nearer 28–31× |
| Poverty line (FPL) | $15,650 + $5,500/person (hh 1) | HHS ASPE 2025 guidelines, 48 states + DC — applies to coverage year 2026 per IRC §36B(d)(3)(B) · asOf 2025-01 |
| Applicable percentage & cliff | 2.10–9.96% of MAGI; no credit ≥400% FPL | IRS Rev. Proc. 2025-25 (original §36B schedule restored — enhanced PTC expired 2025-12-31) · asOf 2025-07 · legislative uncertainty flagged |
| Benchmark premium (SLCSP) | $625/mo national avg, age 40 | KFF marketplace benchmark premiums 2026, rescaled on the CMS default age curve (21/40/64 = 1.000/1.278/3.000) · asOf 2026-01 · illustrative — real SLCSP is rating-area-specific |
| PV(Social Security) discount | 2.0–2.75% real | FRED TIPS constant-maturity real yields — DFII10 2.25%, DFII30 2.78% · asOf 2026-07-01 · CPI-indexed stream discounts at a real yield |
| Benefit payable share (conservative end) | 77% of scheduled | SSA 2025 OASDI Trustees Report — OASI reserve depletion 2033, continuing income covers 77% · asOf 2025-06 |
| Spending defaults | $35,000 / $78,500 / $150,000 | BLS Consumer Expenditures 2024 — lowest quintile $35,046, mean $78,535, highest quintile $150,342 · asOf 2024 · defaults only, user-editable |
| Pre-65 healthcare treatment | carried across the whole horizon | conservative proxy for lifetime healthcare — Medicare premiums + out-of-pocket after 65 are not separately modeled (v1) |
Formula: required = (spending + withdrawal tax + pre-65 ACA premium) ÷ withdrawal rate − PV(Social Security). The benefit's present value is subtracted from the portfolio side — putting it in the numerator is the classic bug this page corrects. Under-100%-FPL MAGI assumes expansion-state Medicaid at $0; in non-expansion states a coverage gap can apply. Every output is an estimate shown as a range.
Common questions
What is the difference between Lean, Regular, and Fat FIRE? ›
The three flavors describe different spending levels. This page defaults Lean to a bare-bones budget, Regular to a middle budget, and Fat to a comfort budget, seeded from 2024 BLS Consumer Expenditure averages of about $35,000, $78,500, and $150,000. Each flavor gets its own withdrawal band, because a lean budget has no discretionary spending to cut in a bad market sequence and so is treated more conservatively than a fat one.
How much do I need to retire early with the 4% rule? ›
The 4 percent rule traces to Bengen's 1994 study, which found a roughly 4.15 percent safe withdrawal rate over 30 years. This calculator notes that 25 times spending is a 30-year figure, so a 45-year retirement lands nearer 28 to 31 times. It applies flavor-specific bands rather than one rate: about 3.25 to 3.5 percent for lean and 3.7 to 4.25 percent for regular and fat, then adjusts for your horizon.
How does Social Security affect your FIRE number? ›
This page subtracts Social Security as a present value on the portfolio side, not by netting it out of spending. The shortcut that treats the check as starting the day you retire understates the number, because the benefit does not begin until your claim age and the years before it are a bridge you self-fund. The present value discounts the CPI-indexed stream at a real yield drawn from TIPS.
What is the 2026 ACA subsidy cliff and how does it affect early retirement? ›
For 2026 the 400 percent federal-poverty-line cliff is restored after the enhanced premium tax credit expired on December 31, 2025. One dollar of MAGI over that line forfeits the entire premium tax credit, which the page notes can be a five-figure annual jump for a fat budget. The calculator itemizes this per flavor, since a withdrawal that lifts MAGI over the line changes the number. Congress may still act, so treat subsidy figures as projections.
Related
- Coast FIRE
When compounding alone can finish the job.
- Barista FIRE
Part-time income, MAGI, and the same ACA subsidy engine.
- Safe withdrawal rate
Where the withdrawal bands come from.
- Methodology
How the parameter bands and data layers are built.