About Calci
Calci is a collection of free, browser-based calculators for finance, construction, health, and everyday tasks. It's published under a single brand rather than a named author, so this page explains how the calculators are actually built instead of who built them.
Every formula is cited
Every calculator names the formula or standard it uses and states its source. Where a source has a stable public URL, a government page, a standards body, a peer-reviewed study, or a DOI, it's linked directly so you can check it yourself. Where a source doesn't resolve to a reliable public link, it's still named in full (author, title, publisher, year) rather than left as an unattributed "industry standard."
Figures that can change carry a date
Some calculators rely on figures that move over time: tax thresholds, fuel prices, interest rates, and similar externally set numbers. Any calculator built on a figure like that shows a visible "last updated" date next to its assumptions, so you can tell at a glance how current it is instead of assuming every number on the page is fixed.
Uncertainty is disclosed, not hidden
Some of the numbers a calculator depends on come from ranges, estimates, or sources that don't fully agree with each other. Where that's the case, it's stated plainly in that calculator's own assumptions, rather than resolved by quietly picking one figure and presenting it as more certain than it is.
Nothing you enter leaves your browser
Every calculation runs client side, using JavaScript that ships with the page. Whatever you type into a calculator, income, weight, a loan balance, or anything else, is never sent to a server, logged, or stored by Calci. Closing or refreshing the page clears it completely. See the Privacy page for the full picture, including the analytics service used to measure site traffic.
What Calci is not
Calci doesn't claim a named author or a team of credentialed experts. The credibility on offer here is methodological, sourced formulas, disclosed assumptions, and dated constants, not a claimed pedigree. Nothing on this site is financial, medical, legal, tax, or engineering advice; see Terms for the full disclaimer, and use Contact if you spot something that looks wrong.