Methodology

OverCalculator is the organizational publisher of this calculator utility and reference product. The objective is to make each calculation usable and reproducible: identify the inputs, state the method and important assumptions, implement the formula, and explain what the output does and does not mean.

Sources and method selection

We prefer the closest available primary or authoritative source for a method: legislation and regulator publications for regulated definitions, government or standards-body material for official values and units, original technical documentation, and peer-reviewed or institutional material where appropriate. Established mathematical definitions may not need a time-sensitive source. Competitor pages are not treated as authority when a primary source is available.

A page should identify a source when it materially supports the formula, threshold, classification, or assumption. Sources do not eliminate judgment: where accepted methods differ, the tool should state which method it uses, its scope, and any choice that could change the result.

564 calculator pages currently carry a sources: block listing the cited material, and a coverage gate fails an eligible calculator page that ships without one.

Formula implementation and checking

Each tool connects labeled inputs, units, validation rules, calculation logic, and displayed outputs. Checks may include recalculating a published example, comparing independent arithmetic with the live output, exercising ordinary and boundary inputs, and checking conversions and rounding. The scope depends on the calculator.

Executable verification evidence is now part of the catalog rather than an expansion in progress. 530 calculator pages carry a verificationCases block: for each page, normal, boundary, and invalid cases are written from the page's own article math, with expected outputs recorded in the same shapes the form displays. yarn verify:cases executes every fixture against the real form computes. The runner currently covers 512 eligible (canonical, non-archived) pages with zero failures, including 24 pages whose forms keep their compute module-private: those execute through a documented verbatim compute registry (scripts/verify-case-computes.ts) that replicates the colocated form's arithmetic, branching, and readout construction, and the runner tags those pages "override" in its report so any drift between the replica and the form shows up as assertion failures.

New verification fixtures follow a producer/independent-verifier split: the author who writes the cases does not approve them. A separate verifier independently recomputes each fixture against the article math before it can land, and the vc-coverage quality gate fails any canonical, non-archived, non-Financial calculator page that ships without a verificationCases block, so executable evidence cannot silently drop off a page.

597 pages carry a dateVerified stamp recording when the page's formula, inputs, assumptions, sources, and worked examples were last recomputed and confirmed against the live implementation. Until a calculation has persistent verification evidence, worked examples and manual comparisons are checks—not a guarantee. Users should independently verify consequential results with the relevant institution, authority, or qualified professional.

Automation and organizational responsibility

Automation and AI-assisted systems may support source discovery, drafting, code generation, formatting, and test preparation. Their output can be incomplete or wrong and is not itself a source or proof of accuracy. Claims should be checked against cited material and calculator behavior before publication. OverCalculator, rather than a bylined individual or an automated system, is responsible for the published product.

Updates and dates

A Published date, when shown, means the page was first made available. An Updated date means the formula, inputs, assumptions, sources, explanation, or another user-relevant part of the page was materially changed. Deployment, formatting, or a routine technical rebuild should not by itself change that date.

Stable mathematical tools may need infrequent changes. Tools that depend on rates, thresholds, regulations, recommendations, or external datasets can become outdated and require closer checking. A displayed date describes the recorded page change; it is not a promise that every external value remains current.

Corrections

Reports are assessed against the source, formula, implementation, units, rounding, and explanatory text. Confirmed errors are corrected, and material changes update the page date and may include a visible correction note when readers could otherwise misunderstand earlier results. Differences between valid methods may instead lead to clearer assumptions or additional context. Findings from verification passes that do not block a release are recorded as report-only items and worked into later corrections batches under the same assessment rules. See the full Corrections policy or contact OverCalculator.

Advertising separation

Advertising, when served, is labeled and separate from calculator controls and reference material. Advertisers do not approve sources, methods, outputs, or corrections, and payment does not determine a result. OverCalculator does not present advertising as a recommendation.

Limits

The tools provide general information and estimates, not medical diagnosis or treatment and not financial, investment, tax, legal, engineering, or other professional advice. Inputs, jurisdiction, timing, and individual circumstances can make an otherwise correct general formula unsuitable for a specific decision.