About this site

What Phases is

Phases is a small, independent collection of financial calculators. It started with one tool — a multi-phase compound interest calculator built because most calculators assume a single flat rate for your entire life, when in reality money moves through distinct phases: early career, peak earning, retirement drawdown, each with its own contribution and rate. Phases is growing into a broader set of calculators built on the same principle: model the real mechanics of a financial decision, not a simplified version of it.

Who builds it

Phases is built and maintained by one person, not a company or editorial team. Every calculator is coded by hand, and every explanation is written to be read by someone making a real decision — not to rank for a keyword. Where the underlying rules are new, uncertain, or still being clarified by regulators (as with the Trump Account program), that's stated plainly rather than glossed over.

How it's funded

Phases is free to use and has no required signup. It's supported by voluntary tips and a small number of referral links to products the site's builder actually uses personally, disclosed wherever they appear. As the site grows, some pages may include affiliate links to financial products (lenders, brokerages, tax software) relevant to that calculator's topic. Any such link is clearly marked, and it never changes the math the calculator shows you — the numbers come first.

Accuracy and limits

Every calculator on this site is built for education, not personalized financial, tax, or legal advice. Formulas are checked against official sources (IRS guidance, Treasury publications, CFPB materials) at the time of writing, but tax law and program rules change — always confirm specifics with a qualified professional before acting, especially for newer programs where rules are still being finalized.

How this site handles inflation

Almost every disagreement between two financial calculators comes down to units — whether a number is in today's purchasing power or in the dollars of some future year. Most tools never say. Phases follows four rules, and states which one applies on every page that projects money forward.

1. Never mix units inside one figure, table, or chart. This is the only rule that is never bent. A median taken across results denominated in different years' dollars is not a median of anything — it is arithmetic on incompatible units, and it can reverse the ranking of the underlying results.
2. Always label the unit where a headline number appears. A projection is not wrong for being nominal. It is only misleading when it is unlabelled and the reader assumes today's dollars.
3. Let the subject choose the unit, not the house style. Long-horizon purchasing-power questions belong in real terms. Quantities that are contractually or statutorily nominal stay nominal — a mortgage payment is fixed in nominal dollars, and US capital gains tax is assessed on the nominal gain because basis is not indexed for inflation. Forcing those into real terms would produce the wrong answer, not a more honest one.
4. Where nominal is correct but the horizon is long, show a today's-dollars reference alongside it. You get the number that is technically right and the number that means something.

Two consequences worth knowing. The relevant deflator is not always CPI — for a college-funding goal it is tuition inflation, which has historically run well above general prices, so the 529 calculator uses that instead. And converting to real terms never changes a like-for-like comparison: whether Roth beats Traditional, whether dollar-cost averaging beats a lump sum, or whether a retirement plan survives are all measured in matching dollars on both sides, so the answer holds either way. Inflation changes what a result means, not which option wins.

Get in touch

Found a calculation that looks wrong, or have a calculator you'd like to see built? Email hello@phasecalc.com — messages reach the person who builds the site directly.