How I Keep Money Sites Accurate: An E-E-A-T Playbook for YMYL

When you publish numbers people make decisions on — a mortgage payment, a paycheck, a retirement contribution — being wrong isn't a typo, it's a broken promise. Google files this content under YMYL, "Your Money or Your Life," and holds it to the highest trust bar it has. But "be accurate" is a platitude until you turn it into a system. Here's the actual process I use to keep money sites correct at scale, and why the same discipline is what earns E-E-A-T.

Accuracy is an architecture problem, not an effort problem

The instinct is to treat accuracy as care — check your work, be diligent. That doesn't scale. On a site with dozens of calculators, "be careful" fails the moment the same constant lives in six places and you update five of them. Accuracy has to be built into how the site is structured, so that being right is the default and being inconsistent is impossible.

Everything below is a way of removing the opportunities to be wrong, rather than relying on catching mistakes after the fact.

1. One formula engine, never twenty copies

The math lives in exactly one place. On FigureMoney, all 25 calculators import from a single finance library — amortization, compound interest, effective-rate, present-value math written and checked once, then reused everywhere. The mortgage page and the auto-loan page physically cannot disagree about how interest compounds, because they're calling the same function.

This is the highest-leverage accuracy decision you can make. Twenty-five separate implementations of the same formula means twenty-five chances for one to drift; one implementation means a fix or a correction lands everywhere at once. When your entire pitch is "our numbers are right," you cannot afford copies.

2. One source of truth for every constant

Rates, brackets, contribution limits, deductions — every constant lives in one dataset, not sprinkled through the code. FigureMoney's state tax pages all read from a single 2026 tax file; the 401(k) and IRA calculators read the year's IRS limits from one place. When the numbers change next year, they change in one file and propagate to every page on the next build.

The failure this prevents is the worst kind on a money site: a page that was right when you published it and quietly went stale. Centralizing the constants means a page can't rot in isolation — and it lets you date-stamp the whole dataset, so both readers and crawlers can see the numbers reflect the current year.

3. Show the work — every formula, constant, and source, on the page

A number with no explanation asks the reader to trust you. A number with the formula, the constants, and the authoritative source behind it lets the reader verify you — and verifiable beats confident every time, with humans and with Google's quality raters. Every FigureMoney calculator carries a methodology block that publishes the exact formula and a worked example, plus a standards block that names the real regulation behind it — the IRS contribution limit, the amortization convention, the withholding rule.

This is the difference between a thin calculator that asserts a monthly payment and one that shows you how it got there. In a YMYL niche the trust layer isn't decoration around the product — it is the product.

4. Keep the proof crawlable

A methodology block only builds trust if it's actually seen. The rule everywhere on my sites: the full explanation is always in the server-rendered HTML, hidden with CSS when collapsed rather than removed from the page. A reader gets a clean UI; a search-quality rater, an ad reviewer, and an AI crawler all get the complete depth whether or not a human expands it. You never trade the tidy layout for the crawlable substance — you keep both.

5. Name a real author behind the numbers

The first E in E-E-A-T is Experience, and YMYL is where it's weighted hardest — Google wants to know a real, accountable person stands behind the advice. Across my network, every property references the same David Miles author entity, linked back to one profile on this hub. That consistent identity is a stronger trust signal than an anonymous site asserting expertise about your money. If you operate in a high-trust niche, wire a real author into your structured data from day one; it's worth more than another calculator.

This isn't just for finance

YMYL covers anything that can affect someone's health, safety, finances, or major life decisions — and the playbook travels. On RemodelCalculators, the same discipline applies to code-compliance and structural estimates: one source of truth for the numbers, the standard named on the page, the method shown. Wherever a wrong output costs the reader real money or real safety, the answer is the same — centralize the logic, cite the source, name the standard, show the work, and sign it with a real name.

Why this matters for your business

If you operate anywhere near a high-trust topic, the winning move is rarely more content — it's more verifiable content, produced by a system that makes inaccuracy structurally hard. Show the formula, cite the source, name the standard, keep it crawlable, and stand behind it with a real identity. Trust a reader can check is what ranks in the categories Google is most careful about.

"Could a skeptical reader verify every number on this page?" is the bar. Build the system so the answer is always yes. The rest of the build logs are here.