About calcu.lol
Last updated: 26 July 2026
calcu.lol is a collection of 312 visual calculators, available in 8 languages, free for anyone to use.
The premise is simple: a calculator that only prints a number teaches you nothing. Every calculator here is paired with a visualization — a diagram, a chart, a geometric figure — because the goal is to help you understand the math, not just get an answer.
What you'll find here
Calculators for everyday math, geometry, finance, science, statistics, and unit conversion — from percentages and fractions to loan amortization, triangle solving, and orbital mechanics. Each one shows its formula, explains its result, and draws what is happening.
Every result is shareable: the numbers you enter are reflected into the page's address, so copying the link is all it takes to show someone exactly what you calculated.
Free, with nothing to sign up for
The site is free to use, with no accounts, no ads, and no tracking cookies. There is nothing to install and nothing to subscribe to.
Who runs it
calcu.lol is a personal project built and operated by David de León (GitHub: @dvddvd300). There is no company behind it.
The best way to reach the operator — for questions, corrections, or suggestions — is through the GitHub profile github.com/dvddvd300.
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How the numbers are produced
If you want to know how the calculators actually compute — the precision they use, where the math runs, and how it is tested — that has its own page: "How we calculate", linked in the footer.