Methodology

Calculators

Every interactive calculator on this site — on the tools page and embedded in posts — states its own assumptions on the page it lives on: the growth rate it assumes, the contribution limit or tax bracket it uses, and what it deliberately ignores (fees, state taxes, sequence-of-returns risk, and so on). None of them are personalized financial projections. They're simplified models meant to make a specific trade-off — Roth vs. Traditional, DCA vs. lump sum, needs vs. wants — legible in dollars, using round, stated numbers rather than your actual financial details.

Charts built from primary data

Where a post includes an original chart, the data behind it is compiled directly from the primary source named in the post's sources — the Federal Reserve/FRED for rate and macro series, the IRS for tax figures, the SEC for filings and ETF flow data, the Social Security Administration for COLA and benefit figures, CMS for Medicare figures. I'm not aggregating a secondary site's already-processed numbers; I'm pulling from the same release the primary source publishes and building the visualization myself.

Projected vs. finalized figures

Some posts — next year's tax brackets, a proposed contribution limit, a not-yet-final program rule — necessarily use projected figures ahead of an official release. Those posts say explicitly that the number is a projection, explain how it was projected (typically by applying the same inflation-adjustment formula the agency itself uses to the latest available inflation data), and get a real “Updated” pass once the official number is out.

What “primary source” means here

In practice: irs.gov, sec.gov, federalreserve.gov and fred.stlouisfed.org, ssa.gov, cms.gov, cbo.gov, treasury.gov, bls.gov, and — for legislation — the actual bill text or a nonpartisan summary from CRS. A company's own SEC filing is a primary source for its own numbers; a news article summarizing that filing is not, and I try not to cite it as one.

Limits

All of this is still one person's independent research, not a peer-reviewed publication or a licensed advisory service. Models simplify. Projections can be wrong before the official number lands. If you find an error in a source, a formula, or a figure, I want to know — see the Corrections page.