About TrueCalc Pro
Ten calculators, built the boring way: static HTML, no tracking, and the formula printed on every page.
Why this exists
Search for a calculator and you will find plenty of them. Most are buried under three advertising slots, a cookie banner, a newsletter pop-up and a 2 MB JavaScript bundle. You wait four seconds to divide two numbers, and somewhere a data broker learns that you were looking up loan repayments.
TrueCalc Pro is the opposite of that. Every page is static HTML with a small amount of vanilla JavaScript. There is no framework, no tracking script, no advertising network and no account system. A calculator page weighs a few dozen kilobytes and is usable the instant it renders.
How it is built
Hand-written HTML5, CSS3 and ES6 JavaScript. No React, Vue or Angular — not out of nostalgia, but because a calculator does not need a virtual DOM, and every kilobyte of framework is a kilobyte the visitor waits for. The whole site is a folder of files that any static host will serve.
Calculations run in your browser. That is a privacy decision first and a speed decision second: if the arithmetic never leaves your device, there is nothing to leak, log or subpoena. It also means the calculators keep working on a plane, in a lift, or on a hotel connection that has given up.
Accuracy and honesty
Every calculator shows the formula it uses, and several show the working step by step. Where a result is an estimate rather than a fact — body mass index, calorie requirements, loan quotes before fees — the page says so in plain language and explains what the number cannot tell you. A calculator that hides its assumptions is worse than no calculator at all.
The maths is covered by an automated test suite that checks every formula against known-good values, including the awkward edge cases: leap-year birthdays, zero-interest loans, stacked discounts, temperatures below freezing. If a change breaks a result, the tests fail before the change ships.
Accessibility
The site targets WCAG 2.1 AA. Everything works from the keyboard, form fields have real labels, errors are announced to screen readers, focus indicators are never removed, and the colour palette meets contrast requirements in both the dark and light themes. Results update in a live region so assistive technology announces them without stealing focus.
Who runs it
TrueCalc Pro is an independent project, not a venture-funded startup with a growth target. It exists because these ten calculations get searched millions of times a month and deserve a decent tool. If something is wrong, unclear or missing, the contact page reaches a real inbox.