Sources
This page lists every external source used by Toolivaro tools and editorial content (PROMPT.md §9). Each entry records the owner, the URL, the version or effective date when known, and the date the source was last checked. Sources are reviewed on a recurring schedule; stale entries are removed or updated.
| Source | Owner | Version | Last checked | Used by |
|---|---|---|---|---|
| Gross Profit Margin: Formula and What It Tells You | Investopedia | Article revision 2025 | 2026-07-15 | Profit Margin Calculator, Gross Profit Calculator |
| Margin vs Markup | Corporate Finance Institute (CFI) | 2025 revision | 2026-07-15 | Profit Margin Calculator, Markup Calculator, Discount Calculator |
| Break-even point analysis | U.S. Small Business Administration | — | 2026-07-15 | Break-Even Calculator |
| How much paint do I need? | Sherwin-Williams | — | 2026-07-15 | Paint Calculator |
| Pricing — payment processing fees | Stripe | — | 2026-08-05 | Payment-Processing Fee Calculator |
| Burn Rate | Corporate Finance Institute (CFI) | — | 2026-08-05 | Cash Runway Calculator |
| Portable Network Graphics (PNG) Specification | W3C | PNG 3.0 (Candidate Recommendation 2025) | 2026-08-05 | Image Resizer, Image Compressor, JPG, PNG & WebP Converter |
| WebP — An image format for the web | — | 2026-08-05 | Image Resizer, Image Compressor, JPG, PNG & WebP Converter | |
| JPEG — The JPEG Standard (ISO/IEC 10918) | JPEG Committee | — | 2026-08-05 | Image Resizer, Image Compressor, JPG, PNG & WebP Converter |
| ISO 8601 — Date and time format | ISO | ISO 8601-1:2019 | 2026-08-05 | Date Difference Calculator, Business Days Calculator |
| Pricing & Business Model | SCORE | — | 2026-08-05 | Billable Hourly Rate Calculator |
| Gravel Calculator — volume, weight and coverage | CalculatorSoup | — | 2026-08-05 | Gravel Calculator |
| Time zone database (tz database / IANA) | IANA | tzdata 2026a | 2026-07-15 | Time Zone Converter, Meeting Overlap Planner |
| Introducing JSON | JSON.org | — | 2026-07-15 | JSON Formatter & Validator, JSON Minifier |
| RFC 4180 — Common Format and MIME Type for CSV Files | IETF | RFC 4180 (October 2005) | 2026-07-15 | CSV to JSON Converter, JSON to CSV Converter |
| RFC 4648 — The Base16, Base32, and Base64 Data Encodings | IETF | RFC 4648 (October 2006) | 2026-07-15 | Base64 Encoder & Decoder |
| Concrete calculator (bag yields) | Quikrete | — | 2026-07-15 | Concrete Calculator |
| Tile installation resources | Tile Council of North America (TCNA) | — | 2026-07-15 | Tile Calculator |
| Flooring installation and care resources | National Wood Flooring Association (NWFA) | — | 2026-07-15 | Flooring Calculator |
| Counting tokens | Anthropic | — | 2026-08-05 | AI Token Counter |
| API pricing | Anthropic | — | 2026-08-05 | AI Token Counter |
| RegExp — JavaScript reference | MDN Web Docs | — | 2026-08-05 | Regex Tester |
| GNU Diffutils Manual | GNU Project | — | 2026-08-05 | Text Diff Checker |
| RFC 3339 — Date and Time on the Internet: Timestamps | IETF | RFC 3339 (July 2002) | 2026-08-05 | Unix Timestamp Converter |
| RFC 4122 — A Universally Unique IDentifier (UUID) URN Namespace | IETF | RFC 4122 (July 2005) | 2026-08-05 | UUID Generator |
External sources are referenced for verification and explanation. Their content is outside Toolivaro's control; each source is listed here with the date it was last checked so readers can assess freshness.