We built the calculator site we always wished existed.
FCALCULATOR.com was built on a single conviction: every important calculation should be free, accurate, and available to everyone: without sign-ups, paywalls, or cluttered interfaces. Since 2020, we have been building calculators that meet that standard.
We cover finance (loans, compound interest, retirement planning), health (BMI, calorie needs, metabolic rate), mathematics (statistics, hypothesis testing), unit conversions, and date calculations. More are added regularly.
Every calculator on this site uses formulas sourced from peer-reviewed research and authoritative organisations:
Our editorial team reviews each calculator at least once per year to catch any changes in recommended formulas, guidelines, or reference values. Sources are cited on each individual calculator page.
Every calculation runs entirely inside your browser using JavaScript. No personal data: height, weight, income, date of birth, or anything else you enter: is transmitted to our servers. We do not require accounts. We do not store calculation results. What happens in your browser stays in your browser.
Found an error in one of our calculators? Have a suggestion for a new tool? We genuinely want to hear from you. Please use our contact page to reach the team.