About Calcoya
Calcoya — answers, instantly. We build a large, growing library of calculators, quizzes and tests covering everyday questions: money, health, dates, conversions, and a few things that are just for fun.
Calcoya is an independent project built and run in Sydney, Australia, by a small team that designs, codes and checks every tool on the site — it isn't a faceless content farm or an auto-generated aggregator.
Why Calcoya exists
Most calculator sites online are either cluttered with ads before you can find the input fields, or hide a simple formula behind a sign-up wall. Calcoya started from the opposite idea: pick a genuinely useful, everyday question — what will my mortgage repayments be, what's my BMI, how many days until this date, what's 20% off this price — and answer it in one page, instantly, with the working shown rather than a black-box number.
How the tools are built
Every calculator is built from a clearly documented formula, written out in plain language on that tool's own page — nothing is a hidden lookup table. Where a calculator depends on a real-world rate rather than pure arithmetic, we source it from the relevant official body and say so: currency conversion uses the European Central Bank's reference rates via the Frankfurter feed, refreshed roughly hourly; the BMI calculator uses the World Health Organization's standard weight categories; Australian stamp duty figures are checked against the relevant state revenue office. Each rate-based tool shows when it was last verified and against which source, right alongside the result.
If something looks wrong
Formulas change, rates move, and mistakes happen. If a result looks off, tell us which tool, what you entered, and what you expected via Contact — we investigate every report and correct the tool if it's wrong. We'd rather hear about an error than have it sit unnoticed.
How Calcoya is funded
Every tool on Calcoya is free to use directly on this site, with no sign-up and no email required — you get your answer instantly. We keep the site running with unobtrusive advertising, not by charging visitors. Businesses can also embed Calcoya calculators and quizzes on their own site as a lead magnet — see Embed on your site for details. Advertising and embed subscriptions are the two things that keep the free tools free.
What Calcoya isn't
Every health, financial or "for fun" tool is labelled accordingly — see each tool's page for specifics. We don't provide financial, medical, or legal advice; our tools give general estimates and information only, and quizzes and puzzle-style tests are for entertainment and self-reflection, not clinical or validated assessments. For anything that matters — a mortgage, a health concern, a legal question — talk to a qualified professional.