Editorial Policy
This page explains where our numbers come from, how we keep them current, and who is responsible for the content. Our goal is simple: every figure a calculator uses should be traceable to an official source and kept up to date.
Our principles
- Official sources first. Rates, thresholds, brackets, contribution limits and allowances come from the responsible authority for each country — for example the IRS in the United States, HMRC in the United Kingdom, the ATO in Australia, and the CRA in Canada.
- No invented numbers. We never guess a financial constant. If a value is not published by an official source, we do not use it.
- Show the workings. Every tool explains its formula and lists the parameters it uses, so you can see exactly how a result is produced.
- Independence. Our results are not influenced by advertisers or affiliate partners. Sponsored placements, where they appear, are clearly separated from the calculators and their outputs.
Where our figures come from
Each calculator draws its rates and thresholds from a central parameter store rather than from numbers hard-coded into the page. Every parameter records the source it came from and the date it takes effect. On each tool page, the “Data sources & parameters” section lists these values together with a link to the official source and the date each was last updated — so any figure can be checked at a glance.
How we keep figures current
Keeping hundreds of calculators current by hand would be unreliable, so we combine automation with human review:
- Automated monitoring. A scheduled process reviews our parameters on a regular cycle, flagging any value that is approaching its expiry, has passed its valid-to date, or predates the current tax year for its jurisdiction.
- Scheduled data feeds. Market-linked figures, such as central-bank reference rates and exchange rates, are refreshed automatically from their published sources.
- Human review. Statutory figures — tax brackets, allowances and contribution limits — are checked and updated by a person against the official publication when the authority announces a change, for example after an annual budget or an indexation update.
- A reason for every change. When a value changes we record why (for example, “annual indexation” or “central-bank rate decision”), and that reason is shown next to the figure on the tool page.
How our content is written and reviewed
Each calculator ships with an explanatory article written for a general audience, covering what the tool does, how the calculation works, a worked example, and answers to common questions. Content is written in plain language, reviewed for accuracy against the same official sources as the figures, and revisited when the underlying rules change. The author responsible for the content is shown at the end of every tool page.
Accuracy and limitations
We work hard to be accurate, but our tools provide general information and estimates, not personal tax, legal or financial advice. Real outcomes depend on individual circumstances and on details a general calculator cannot capture. Always confirm important figures with the relevant authority or a qualified professional before acting on them.
Telling us about an error
If you believe a figure or explanation is wrong, we want to know. Please see our Corrections policy for how to report it and how we respond.