Terms of use, in plain words

Last updated: 6 August 2026

Who we are

CalcOtter (calcotter.com) is operated by Iris Consulting and Engineering (Pty) Ltd, a private company registered in South Africa. You can reach a human at hello@calcotter.com. Using the site means you accept these terms. If anything here is unclear, write to us before you rely on it.

What the service is

CalcOtter is a collection of free calculators that run entirely in your browser. There is no account, no sign-up, no paywall and no premium tier. Every calculator states the formula it uses, and the results appear on the same page as the inputs so you can check the arithmetic yourself. We fund the site with a single clearly-labelled advertisement per page.

The results are estimates, not advice

This is the important part. Every number on this site is the output of a published formula applied to the figures you typed. It is not financial, tax, legal, medical or nutritional advice, and it is not a substitute for a professional who knows your circumstances.

Financial calculators assume the rate you enter stays fixed for the whole term and ignore fees, initiation charges, insurance, tax and rate changes — so a real quote from a real lender will differ, usually upward. Health calculators use population-level screening formulas: BMI does not distinguish muscle from fat, a calorie estimate is a starting point that individual metabolism moves by hundreds of calories, and a due date is a forty-week estimate that most births do not land on. Date calculators follow the proleptic Gregorian calendar and do not know about your local public holidays or leave policy.

Use the numbers to think with, to sanity-check a quote, and to make a professional conversation faster. Do not use them as the sole basis for a decision that matters.

Accuracy, and what we do when we are wrong

We test the mathematics against published reference values before changes go live, and we correct errors as fast as we can once we know about them. But we provide the site "as is": we do not warrant that every result is free of error, that the site is always available, or that it fits any particular purpose. To the fullest extent the law allows, we are not liable for loss arising from your use of, or inability to use, the site — including decisions taken on the strength of a result. Nothing in these terms limits liability that cannot lawfully be limited, including liability for death or personal injury caused by negligence, or for fraud.

Your inputs stay yours

The calculations happen on your device. Loan amounts, body measurements, dates and every other figure you type are processed in your browser and are not transmitted to us — there is no server doing the maths, because the pages are static files. We therefore hold no record of what you calculated and could not produce, sell or surrender one. The privacy page sets out what our analytics do and do not see.

What you may do with the site

Use the calculators as much as you like, for personal or commercial purposes, including quoting a result to a client or a bank. Link to any page freely. Quote a paragraph with attribution. What you may not do is scrape the site systematically, republish its pages or explanatory text as your own, use it in a way that degrades it for other people, or present its output as professional advice you are qualified to give.

Our content and yours

The calculators, the explanatory writing, the design and the code are our copyright. The underlying mathematics is not ours and cannot be: amortization, the Mifflin–St Jeor equation and the international definition of an inch are public knowledge, and we cite them precisely so you can verify them elsewhere. Anything you type remains yours; we never see it.

Advertising

One advertisement appears on each page, in a fixed reserved space that does not move the content or cover an answer. It is served by a third-party network and its contents are not chosen, endorsed or checked by us. We do not accept paid placements inside the calculators or the articles, and no advertiser influences a result.

Availability and changes

The site is free, so we make no uptime promise. We may change, add or retire calculators, and we may update these terms; the date at the top shows when they last changed, and material changes will be obvious on this page rather than announced by email — we do not have your email.

Law

These terms are governed by the law of the Republic of South Africa, and the South African courts have jurisdiction. Nothing here removes rights you have under the Consumer Protection Act 68 of 2008 or any other law that applies to you. If a court finds one clause unenforceable, the rest stands.