How we test
Review process
Each guide serves one reader task. We redo calculations using the stated inputs, units and formulas, disclose rounding and omitted costs, and compare alternatives over matching periods and conditions.
Sources and reference dates
We prefer direct sources such as public authorities, manufacturers and official documentation. Changing rates, prices, rules and specifications include reference dates and sources. We explain what the evidence means instead of merely collecting links.
Calculator checks
We try calculators with normal, empty, boundary and invalid inputs. On narrow and wide screens, we check that results include units, assumptions and a plain-language explanation.
After publication
We reopen changed public pages on phones and computers and check text, links, images, tables and calculations. Correct arithmetic still needs an explanation of its meaning and limits.
Limits
Tax, health and contract guides provide general information, not personal diagnoses or guaranteed outcomes. Published specifications are distinguished from our own measurements, and unmeasured performance is labelled as such. Check current official sources and seek qualified advice where personal facts matter.