Sources verified · May 22, 2026
How long until work is optional?
The same monthly outflow, but viewed from the other side — your savings rate. Enter take-home and spending; we’ll show the math from MMM's “Shockingly Simple” explainer and let you see what a higher rate would shave off.
New here? See it work with example numbers:
What this tool does and doesn’t do
- Does: closed-form years-to-FI projection using the Trinity Study’s 4% safe withdrawal rate and a 5% real (after-inflation) return on invested assets. Handles an optional existing-invested-assets starting balance. Surfaces a savings-rate sensitivity table (+5pp / +10pp / +15pp), a withdrawal-rate table (3% / 3.5% / 4% / 4.5%), and an optional Social Security / pension view that lowers the target.
- Doesn’t yet: sequence-of-returns simulation (Monte Carlo), tax modeling on growth or withdrawal, the timing of when Social Security or a pension actually starts (the future-income view assumes it covers spending for the whole retirement), healthcare-cost modeling for early-retirement years, asset-allocation guidance, or per-account-type breakdowns (401k vs taxable vs Roth).
- This is a closed-form projection, not a financial plan. The 5% real return and 4% withdrawal rate are widely-cited conventions, not guarantees — actual outcomes depend on sequence-of-returns, taxes, policy changes, and life events. Treat the years as a planning anchor, not a promise.