Business
How the site expects to sustain itself, declared before it does: the engine and the widget under your brand, the API with a key and a service level, and integration. Not advertising, not placements, not the comparison pages.
Written and edited by Pablo Ruiz QuinteroSources checked September 15, 2026Written and maintained by Pablo Ruiz Quintero; last reviewed 2026-09-15What is on offer
Three things, all built on the engine that runs this site. A white-label calculator: the same calculator under your brand, on your domain or embedded, with the same sources and dates visible to your users and updated by us. An API licence at volume: the free API is limited to sixty requests a minute; a licence removes the limit, adds a key and a service level, and returns the same JSON with provenance. And integration: the engine as a package for payroll, HR and fintech products that need per-paycheck figures with a documented source for every constant.
What is not on offer
Advertising on any page. Affiliate placements. Paid mentions in guides or comparison pages. Access to reader data, of which there is almost none. A favourable comparison. The editorial policy is the contract with readers and it is not for sale.
Why this engine
Every constant carries its document and date; the verification log is public; corrections are public; the tests run against the agencies' own examples; and the AI, where you want it, is held to explaining computed figures. For a product whose users will compare its output with their stubs, provenance is the feature. The methodology page is the specification.
How to start
Write through the contact page with what you are building and the volume you expect. A reply comes from the author, not a sales team.
Sources
An estimate for planning, not tax or payroll advice.
Related
- API
The free tier and its limits.
- Embed
The free widget.
- Methodology
The specification of the engine.