About us
Who we are
free-calculator.app is created by the free-calculator.app team in Bydgoszcz, Poland, in cooperation with Fundacja Bezpieczeństwa i Obrony (National Court Register no. 0000299337).
What we do
We build free online calculators – for salaries and taxes, loans and mortgages, health, dates and everyday maths – in 12 languages. They work without registration, and the numbers you enter are calculated in your browser and are not sent to us.
How we build and check the calculators
- Tax and payroll calculators follow the rules in force in each country for 2026, based on official sources: tax authorities, social security institutions and the published laws and withholding tables. The sources are listed on each calculator page.
- Every calculator is checked against worked examples published by the authorities or by recognised payroll and tax services before it goes live.
- Health calculators use established formulas, such as the WHO BMI categories, the Mifflin-St Jeor equation and the U.S. Navy body fat method.
- We update the calculators when rules change and review all tax rates at the start of each year.
Limitations
The results are estimates for information only. They are not financial, tax, legal or medical advice. Individual circumstances – deductions, allowances, contracts or health conditions – can change the result, so please check important decisions with a qualified adviser, your employer or a doctor.
How the site is funded
The site is free because it shows advertising (Google AdSense). Advertisers have no influence on the calculators or their results.
Contact
Found an error or missing a calculator? Write to us – we read every message.