About Renditra

Why this site exists

Most financial calculators available online return a gross figure and stop there. They ignore the fact that the same investment is taxed at 26.375 percent in Germany, at a progressive scale in Spain and at anything between zero and 33 percent in Italy depending on the wrapper. Some are simply out of date — in 2026 a number of French simulators still calculate with a flat tax rate that changed in January.

Renditra was built on a narrow premise: a calculator is only useful if it reflects the rules that actually apply to the person using it. Translating an English tool into five languages does not achieve that. Rebuilding the calculation around each country's own law does.

The site launched in September 2026 and is being expanded one tool at a time.

Who is behind it

Renditra is operated by Meryem Bilge Seyhun as a sole proprietorship.

Content, calculation methods and technical development are handled by Ahmet Seyhun, a web developer and SEO specialist based in Istanbul who has been building and maintaining websites for over a decade.

The calculation logic and methodology are reviewed by Mehmet Dığış, a public finance graduate and self-employed accountant. His review covers the structure of the calculations and the internal consistency of the tax logic; the country-specific rates themselves are verified against the relevant legislation.

A point worth stating plainly: we are not financial advisers, tax advisers or economists. What we do is read the applicable legislation, implement it correctly in code, cite the source on the page, and say clearly what a given calculation does not cover. Where we are uncertain, we write that we are uncertain rather than rounding it away.

How the site is funded

Renditra is funded by display advertising. We accept no commission from banks, brokers, lenders or insurers, and no product is ever recommended in exchange for payment.

This matters for a financial site: where our content compares products or wrappers, the conclusion is driven by the arithmetic, not by who pays. If that ever changes, this page will say so.

Corrections

If a figure looks wrong to you, it may well be. Write to info@renditra.com with the page and the values you entered. Reports are checked against the legislation and corrected where warranted, usually within a few days.