Savings Rate to FI — years to independence
Most FIRE calculators hand you one clean date built on a made-up return. This one decomposes the growth rate you actually keep — market return − fund expense − advisory fee − tax drag, deflated to real dollars — solves the years-to-FI equation in closed form, and reports a range (p5 / median / p95) from 1928–2025 rolling real returns. Estimate, not advice.
Projected portfolio at the median FI horizon
real $ · p5 · median · p95Real portfolio value at the median years-to-FI horizon, across 1928–2025 rolling return outcomes: coral = the p5 (weak-market) shortfall, green = median (≈ your FI number), lime = the p95 (strong-market) surplus. This is return-level uncertainty, not a sequence-of-returns simulation.
Savings rate → years to FI
curve with return-level bandX axis: savings rate 5–85%. Aqua = years at your decomposed rate; the shaded fan spans the p25–p75 of rolling historical real returns net of your fees; the mint tick marks your savings rate. Years are capped at 60 for display.
Fee tornado — in years, not basis points
Δ years to FIEach bar re-solves years-to-FI with the extra annual fee dragged off the market return. Fees compound against you for the whole accumulation, which is why a flat-sounding 1%/yr shows up as years of additional work.
Show the math ›
Assumptions & sources ›
| Assumption | Value | Source · asOf |
|---|---|---|
| Market return anchor | 10.02%/yr nominal (editable) | Geometric mean of S&P 500 total return 1928–2025, Damodaran (NYU Stern) · asOf 2026-01 |
| Inflation anchor | 3.03%/yr (editable) | Geometric mean of CPI-U Dec/Dec 1928–2025, BLS · asOf 2026-01 · Fisher deflation, not subtraction |
| Fund expense presets | 0.05 / 0.14 / 0.40 %/yr | ICI, Trends in the Expenses and Fees of Funds 2025 (asset-weighted) · asOf 2025-12 |
| Advisory fee preset | 1.00%/yr typical AUM | Datos Insights & Envestnet MoneyGuide, 2026 fee study (avg 0.96%) · asOf 2026-01 |
| Tax drag presets | 0 / 0.7 / 1.9 %/yr | Morningstar tax-cost ratio averages, taxable equity ETF / mutual fund · asOf 2025-12 |
| SWR presets | 3.9% @30yr · 3.5% @35yr · 3.3% @40yr | Morningstar, The State of Retirement Income 2026 (90% success, 30–50% equity) · asOf 2025-12 · plus the classic 4% (Bengen/Trinity) |
| Band construction | p5/p50/p95 rolling real returns | 1928–2025 windows matched to your horizon (5–40yr) · return-level uncertainty only, not sequence-of-returns risk |
Textbook cross-check: at a 5% constant real return and 4% SWR, a 50% savings rate solves to ≈17 years and 75% to ≈7 years — the classic shockingly-simple-math anchors, reproduced by this engine's closed form (tests/verify_savings-rate-to-fi.mjs). All dollars are real (today's) dollars; income and savings are assumed to keep pace with inflation. Everything on this page is an estimate and a projection, not advice.
Related
- Coast FIRE
When your existing pile alone is projected to carry you to the number.
- FIRE Number (Lean/Fat)
Size the target itself before you race toward it.
- Safe withdrawal rate
Why the divisor in your FI number is a range, not 4%.
- Methodology
How the closed form, decomposition, and band are built.