Free online calculators
The numbers in your life, no fine print. No sign-up, nothing to install, and nothing you type ever leaves your device.
Available now
- BMI calculatorYour body mass index, its category, and the healthy weight range for your height.
- Percentage calculatorPercentages, discounts, percentage change, and adding or removing VAT from a price.
- Quadratic equation solverThe two solutions, the discriminant, the exact form and the full step-by-step working.
- Temperature converterCelsius, Fahrenheit and kelvin, both ways and all three at once.
- Roman numeral converterNumbers to Roman numerals and back, up to 3999, with the breakdown.
What Calculoteca is
Calculoteca is a collection of tools that all do the same kind of thing: they give you back a number that says something about your situation. Your body mass index, your monthly mortgage payment, how a savings pot grows over time.
The idea is simple. These calculations exist all over the web, but they usually come wrapped in something: an account to create, an email to hand over, or a wall of ads sitting on top of the tool itself. Not here. Each page does one thing, does it right at the top, and explains it underneath.
There's a technical consequence worth spelling out: since every calculation happens inside your own browser rather than on a server of ours, there is no place where your numbers could end up stored. That's not a promise of good behavior — it's that the place to store them simply doesn't exist.
Tools are added one at a time, and each one is published only once it's been checked against hand-calculated test cases — not once it merely "looks" like it works. This English section is new and starts small; more calculators are on their way.
Frequently asked questions
Do I need to sign up to use the calculators?
No. There are no accounts, no registration, no email required. You open the page, use the tool, and that's it.
Is the data I enter saved anywhere?
No. Every tool does its math inside your own browser. The numbers you type never travel to a server and disappear the moment you close the tab.
Are they really free?
Yes, all of them. The site is supported by discreet advertising placed below the tools, never on top of or blocking them.
Can I trust the results?
The formulas used are the standard ones, and each tool explains exactly what method it uses and what it leaves out. Even so, these are estimates for guidance: they don't replace a binding offer from a lender or advice from a licensed professional.