About NexavoTools
This page is a translation. The French version is the authoritative text.
What NexavoTools is
NexavoTools is a set of free calculators for everyday money questions and for small businesses: VAT, mortgages, compound interest, margins, break-even and percentages. Every result comes with the formula used and, where tax rates are involved, their source.
The site launched in 2026 with some forty file-processing tools. In October 2026 it refocused on calculators, where accuracy and clear explanations matter most.
How the calculations are built
Formulas follow standard financial practice and, for taxes, the official texts. The worked examples on each page are recalculated automatically every time the site is published: a text that no longer matches the calculation blocks the release.
Why everything runs in your browser
A mortgage or salary calculator has no reason to know your income. Here, the page loads the formulas and your browser does the arithmetic. Nothing is sent, and no broker will call you.
Who publishes the site
NexavoTools is published by MATTOIR, a sole trader based in Sainte-Marie, Réunion Island, France. It is an independent, one-person project: there is no team or customer service, but one address, contact@nexavotools.com, read by the publisher. The source code is public under the AGPL-3.0 licence.