Toolivaro

Methodology

Version 2.0 · Reviewed 2026-08-12

Every number on Toolivaro is produced by an explicit method, documented on the page where the number appears. This page describes the standards that apply across all tools.

Calculation standards

  • Explicit formulas. Each tool displays the formula or algorithm it uses, with every symbol defined in plain language. If a formula has multiple accepted conventions, the chosen convention is stated on the tool page.
  • Decimal arithmetic for money. Currency calculations use decimal arithmetic so values like 0.10 behave exactly as a person expects, avoiding binary floating-point artifacts.
  • Full precision internally, rounding only for display. Calculations keep unrounded values until the moment a result is presented. Rounding mode is explicit and consistent (half away from zero unless a tool states otherwise).
  • Validation before computation. Inputs are checked for finiteness, realistic ranges, and units. Zero, negative, empty, and extremely large values are handled deliberately, and the tool tells you when an input combination has no valid answer.

Units and locale handling

Home and construction estimators support metric and imperial units and let you switch between them. Internal calculations are always locale-independent; formatting for display (thousands separators, decimal points) uses your browser's locale. A decimal comma such as “250,00” is accepted where the browser locale makes it the natural input.

Time zones and dates

Time-related tools use IANA time-zone identifiers (for example Europe/Warsaw), never ambiguous abbreviations like “CST”. Daylight-saving transitions are handled explicitly: times that do not exist on a given day and times that occur twice are identified rather than silently resolved.

Local processing

All tools on Toolivaro run in your browser. The code that computes your result is the same code that is unit-tested in this repository, and it executes on your device — inputs are never transmitted, logged, or stored by us.

Correctness and corrections

Each tool ships with unit tests including golden test vectors and boundary cases. Every page records a reviewed date and a version number. If you believe a result is wrong, report a correction; corrections are reviewed, applied, and the page's reviewed date and version are updated. A summary of changes is kept in the changelog.

Sources

Where a formula, rate, or recommendation comes from an external source, the source is listed on the tool page and in the sources registry with its owner, URL, version when known, and the date it was last checked. External content is never used to justify claims Toolivaro cannot verify itself.

Standards and references

Where a number depends on a definition, a convention, or a conversion factor, the choice follows a named, publicly reviewable standard. The standards below are in force across all tools; each is listed in the sources registry with the date it was last checked.

  • SI units and conversion factors — NIST SP 811. Metric–imperial conversions in the home and construction estimators use the exact conversion factors published in NIST Special Publication 811 (for example 1 in = 25.4 mm, 1 US gal = 3.785411784 L, 1 lb = 0.45359237 kg), never rounded shortcut factors.
  • Unit definitions — SI Brochure, 9th edition. The definitions of the SI base units and the formatting of unit symbols follow the current edition of the SI Brochure.
  • Quantities and units — ISO 80000-1. Quantity names, symbols, and dimension conventions follow ISO 80000-1 (second edition, 2022).
  • Dates and times — ISO 8601 and the IANA Time Zone Database. Dates are rendered in ISO 8601 form; time conversions use IANA zone identifiers resolved against tzdata releases, never ambiguous abbreviations.
  • Floating-point arithmetic — IEEE 754 (via ECMA-262). Numeric computations run on IEEE 754 binary64 arithmetic as specified by ECMA-262; monetary paths use decimal arithmetic instead, and display formatting follows the ECMA-402 internationalization API with the reader's locale.

Precision of constants and conversion factors

  • Exact factors at full precision. Conversion factors that are exact by definition (1 in = 25.4 mm, 1 US gal = 3.785411784 L, 1 lb = 0.45359237 kg) are applied unrounded — a factor is never truncated before a result is computed.
  • Conventions are labelled as conventions. Practical rates used by estimators — for example the 350 sq ft of coverage per gallon used by the paint calculator — are industry conventions, not physical constants. They are stated on the tool page with their source.
  • Rounding only at display time. Calculations keep full precision internally and round only the final result, to the decimal places documented on each tool page, under the rounding mode stated there.

Verification, testing, and reproducibility

Every tool ships with unit tests, including golden test vectors and boundary cases. The full suite runs on every change before deployment — 679 tests across 76 files at the time of this review — and a failing test blocks the build. Every page records a reviewed date and a version number, so a specific result can be tied to a specific revision.

Because Toolivaro is a fully static site that computes in your browser, the method is the page: every formula is published on its tool page with its symbols defined and its convention named, so any result can be reproduced by hand from the page itself. Where a formula depends on an external standard or rate, that source is listed in the sources registry with its last-checked date.

How to cite this page

This page is versioned so a citation can name exactly which revision was used — cite the version you consulted. Revisions are recorded in the changelog. Citation metadata (title, author, dates, version, language) is also embedded in this page's HTML for citation managers and scholarly indexes.

Toolivaro Editorial Team. (2026, August 12). Methodology — How Toolivaro Computes Results (Version 2.0). https://toolivaro.com/methodology/

BibTeX:

@misc{toolivaro-methodology,
  author       = {{Toolivaro Editorial Team}},
  title        = {Methodology -- How Toolivaro Computes Results},
  year         = {2026},
  month        = aug,
  note         = {Version 2.0},
  howpublished = {\url{https://toolivaro.com/methodology/}}
}

Limitations

Results are informational estimates, not professional financial, legal, construction, or medical advice. Where a result could be materially affected by a decision — pricing, materials purchasing, or otherwise — confirm it with current data and, where relevant, a qualified professional.