About CalcFolio
Updated
CalcFolio is a free calculator website available in five languages: English (US), Portuguese (Brazil), Spanish (Spain), French (France), and German (Germany). The English edition has more than 160 calculators across personal finance, health and fitness, math and statistics, home and construction, taxes and pay, dates and time, school grades, pregnancy, driving, everyday life, and unit conversions.
What makes a CalcFolio calculator
A calculator is only useful if you can trust the number it gives you. That is why every page follows the same structure:
- Formula and methodology. You can see exactly what is computed, which assumptions are made, and how rounding works.
- Worked examples. Each example is produced by the same code that runs the calculator, so the page and the tool always agree.
- Frequently asked questions. Short, direct answers to the questions people actually ask about the topic.
- Sources. A list of the official or primary references the calculator is based on.
Rules with an effective date
Some calculations depend on laws, tax tables, or official rates that change over time. For those calculators, the rules are stored as a versioned set with the date they take effect, and they are reviewed against official sources. When a rule changes, a new version is added rather than silently overwriting the old one, and the page shows when it was last updated.
Data that updates itself
A few calculators rely on public data series rather than fixed rules. Some of these series, such as Brazil's IPCA inflation index published by the Banco Central do Brasil, are refreshed automatically each month from the official source.
Written for each country
Each language version is written for its own market, not translated word for word. That means local units, currency, number formats, and the authorities readers in that country rely on. Some calculators, such as Brazil's FGTS, only make sense in one country and are offered only there.
Free, with no sign-up
You do not need an account to use CalcFolio. Calculator inputs are processed in your browser and are not sent to our server. The privacy policy explains what little data is involved in serving the site.
Estimates, not advice
Results are estimates based on the information you enter and the rules described on each page. They are meant to help you understand a topic and prepare better questions, not to replace a doctor, accountant, lawyer, or financial advisor.
Contact
Found a mistake, an outdated rule, or a source that should be cited? Write to press@calcfolio.com. Corrections are welcome and taken seriously.