Editorial Policy

How we build a calculator

Every calculator on Fiscalgrove starts from a documented, first-principles formula — the same one a bank, lender, or government calculator would use — which we write out in full on the calculator's own page, not just in the code. Where a calculation depends on a statutory figure (like UK Stamp Duty bands or US PMI removal thresholds) or a widely-used lending convention (like the 28/36 DTI rule), we cite the primary source directly rather than a secondary summary.

How often we re-check figures

Statutory and government-set figures (tax bands, published average rates) are re-verified against their primary source at least every three months, and immediately after any relevant government announcement (a Budget, a rate-threshold change, and so on). Pages carrying this kind of figure show a visible "Rates verified" stamp with the date of the last check and a link to the source we checked it against.

Corrections

If a figure or explanation on Fiscalgrove turns out to be wrong or out of date, we correct it as soon as we verify the report — usually within 2 business days of being notified. Material corrections (anything that would change a calculated result) update the "Last updated" date at the top of the affected page. You can report a suspected error via our Contact page.

Independence

Fiscalgrove does not accept payment, free products, or any other consideration in exchange for favourable coverage of a specific lender, broker, or financial product. Some outbound links to comparison services or brokers are affiliate links, so we may earn a commission at no extra cost to you; these never influence our calculators, our explanations, or which options we show, and each is marked where it appears. See our Affiliate Disclosure for the detail. Where the site carries advertising, it is served by a third-party ad network and is not tied to editorial content or calculator outputs in any way — see our Privacy Policy and Cookie Policy for details on how that advertising works.