How Our Calculators Work
This page explains how the calculators on Teamz Lab Tools are built, where their numbers come from, how often they are reviewed, and — just as important — what they cannot do. It is written so you can judge for yourself whether a result is trustworthy for your situation.
Who builds these tools
Teamz Lab Tools is built and maintained by Teamz Lab Ltd, a software development company registered in the United Kingdom, company number 16106867 (verify on Companies House). We are software engineers, not accountants, solicitors, or clinicians. That distinction matters and we state it plainly on this page and in the disclaimer.
Where the formulas come from
Every calculator implements a published, checkable rule rather than an opinion:
- Tax and payroll tools use the rates, thresholds and bands published by the relevant tax authority for the stated year — for example HMRC in the UK, the IRS in the US, the ATO in Australia. The tax year the tool applies is shown on the page.
- Mortgage, loan and savings tools use standard amortisation and compound-interest formulas. The arithmetic is deterministic and reproducible by hand.
- Sports and fantasy tools use the official scoring rules of the competition, and where a tool uses past performance it names the season the numbers come from.
- Health and fitness tools implement recognised published formulas (for example BMI or BMR equations) and are for general information, never diagnosis.
How results are calculated
Every calculation runs entirely in your browser. Nothing you type is uploaded, stored on our servers, or shared. That is a privacy decision, and it has a side effect worth knowing: because we hold no data about you, a tool cannot account for details you have not entered.
How often tools are reviewed
Tools tied to a dated ruleset — tax years, contribution limits, scoring rules, season data — are reviewed when the governing body publishes a change, and the applicable year is stated on the page. Automated checks run nightly across the site to flag pages whose data has gone stale, whose scripts have broken, or whose structured data is missing. When a source we depend on stops updating, our monitoring raises it rather than letting the page quietly drift out of date.
What these tools cannot do
A calculator applies a general rule to the numbers you give it. It does not know your full circumstances, and it is not a substitute for professional advice:
- Results are estimates for guidance, not official determinations, quotes, or rulings.
- Tax, benefit and legal outcomes depend on personal circumstances, reliefs, and rules a general calculator cannot see.
- Lenders, insurers, tax authorities and courts use their own systems; their figure is the one that counts.
- Health tools are general information and never a diagnosis.
Before acting on a number that affects your money, health, or legal position, check it with a qualified professional. See the full disclaimer.
Found something wrong?
If a formula, rate, or result looks incorrect, please tell us — corrections are treated as priority work, and reports that identify a specific page and the expected value are the most useful. Reach us via the contact page. We would rather be corrected than be confidently wrong.
Independence
These tools are free to use and funded by advertising. Advertisers have no influence over a calculator's formula, its result, or what we publish. We do not accept payment to change an outcome.