Editorial policy

Last updated: September 20, 2026

In short

• Every calculator and article is written by a named expert and checked by a second expert before it goes live.
• Formulas and worked examples are recalculated by hand and in a spreadsheet.
• Each page shows who wrote it, who reviewed it and when it was last updated.
• If something is wrong, you can report it from any calculator or article, and we fix confirmed errors.

Our mission

averagecalculator.io gives free calculators for averages and everyday statistics, with the working shown for every answer. We want you to leave with the right number and a clear idea of how it was reached. A result you cannot check is only half an answer, so every calculator shows the formula, your numbers inside it and the steps in between.

The site covers statistics only: averages, spread and the measures around them. New statistics calculators are added over time, and each one goes through the same process described on this page before it goes live.

Who creates our content

Our pages are written and reviewed by statisticians and math teachers. They include PhD statisticians, a biostatistician, an industrial engineer and classroom teachers with years of experience explaining averages to students. You can see each person’s background, experience and the pages they worked on at Our experts.

Every expert on the team both writes and reviews, but never reviews their own page. A page written by one expert is always checked by another.

How we build a calculator

1. We start with the question people are trying to answer, such as “what is my weighted grade?” or “what is the average of these times?”.
2. We write down the formula, define every term and note where it stops working, such as an empty list or weights that add up to zero.
3. The calculator is built and tested with hand-worked examples, spreadsheet checks and awkward inputs. Our Sources and methodology page shows the exact tests for each tool.
4. A writer adds the explanation, worked examples and FAQs.
5. A reviewer checks the math and the explanation, and the page goes live only after they sign off.

How we write articles

Articles answer the question first, then go deeper. Each one uses worked examples with real numbers, because an example you can follow teaches more than a paragraph of theory. Where a topic has a common trap, like using the mean when the median fits better, we name it directly.

Formulas and spreadsheet functions in articles are tested before publishing. If an article shows an Excel formula, we have run it in Excel or Google Sheets and checked the result.

Expert review

The reviewer checks three things:

• The right formula was used for the question and the math is correct.
• The explanation is accurate, not only easy to read.
• The limits of the result are stated, for example when an average can mislead because of an outlier.

The reviewer’s name and the review date appear on the page, so you can see who checked it.

Fact-checking

Every number, formula and definition on a page is checked against its source by someone other than the writer. If a claim cannot be checked, it is rewritten or removed.

Original content

Everything on this site is written for this site. We explain formulas and ideas in our own words and do not copy text from other websites or books.

Corrections

If we get something wrong, we fix the calculation first, then the explanation and examples, and then check the fix against a spreadsheet before closing the report. If an error could have given someone a wrong answer, we add a note on the page saying what changed and when.

To report a mistake, use the Report an error link at the bottom of any calculator or article, or email [email protected]. Please include:

• the page or calculator
• the numbers you entered and the result you got
• the result you expected and how you worked it out

We reply to every report, whether or not the page turns out to be wrong. If the calculator was right but the page confused you, we rewrite that part so the next reader does not get stuck in the same place.

Updates and review dates

Each calculator and article shows the date it was last updated. We recheck pages when a reader reports a problem, when a spreadsheet function or common convention changes, and when we add features to a tool. When a formula changes, the examples and explanation change with it, so the page never disagrees with itself.

Advertising and independence

averagecalculator.io is free, and ads from Google AdSense help pay for it. Ads are kept apart from our content and are clearly shown as ads. Advertisers have no say in how a calculator works, what we write or which results we show.

Contact

Questions, corrections and feedback: [email protected], or use our contact page.