Sobre Nós
Tornamos a análise estatística avançada acessível a todos.
Who runs this site
Jack Shi · Founder of Clooms · Independent Developer
Jack Shi builds and maintains Standard Deviation Calculator: the calculator engine, the worked examples and the guides. He is an independent developer and the founder of Clooms, where he builds and runs focused web utilities.
What the site does
- A free standard deviation calculator with both sample (n − 1) and population (N) modes, plus variance, mean and related results.
- Task pages for sample, population, grouped-data and relative standard deviation (%RSD) calculations, and a z-score calculator.
- Guides on choosing a formula, z-scores, confidence intervals and spreadsheet functions, with worked examples.
Calculations run in your browser; the numbers you type are not sent to a server to compute the result.
How the numbers are checked
- Formulas follow the standard definitions in the NIST/SEMATECH e-Handbook of Statistical Methods: the variance divides the sum of squared deviations from the mean by n − 1 for a sample and by N for a population.
- Worked examples marked “Computed with this site's calculator” are generated by the same code as the calculator, and their buttons open those exact numbers in it. Example: the scores 2, 4, 4, 4, 5, 5, 7, 9 (English) give σ = 2 as a population and s ≈ 2.138090 as a sample (computed 2026-11-02).
- Where a guide compares Excel, Google Sheets, Python, NumPy, pandas or R, it names the function and, if the result was run, the version and date.
- Automated checks in the code compare guide examples with hand-computed values.
Corrections and contact
If a result, formula or example looks wrong, email the numbers you used and the page link. When an error is confirmed, the page is corrected and its updated date is changed.
A Nossa Missão
Acreditamos que as ferramentas estatísticas de nível profissional devem ser acessíveis a todos. Quer sejas um estudante a aprender estatística, um investigador a analisar dados ou um profissional a tomar decisões baseadas em dados, standarddeviationcalculator.app proporciona-te a precisão e os conhecimentos de que necessitas.
A standard deviation calculator is an educational tool when it explains both the arithmetic and the interpretation. Statistical literacy refers to the ability to understand what a number says about spread, uncertainty, or consistency in the underlying data rather than treating every output as a self-contained fact.
Editorial Standards
We organize calculator pages around definitions, tables, FAQs, and citations because statistical content is easier to trust when a reader can verify the vocabulary and assumptions. A statistical definition is a compact statement of what a metric measures, while an interpretation guide explains how to use it in context.
| Content element | Purpose | Reader benefit |
|---|---|---|
| Definition block | States what the concept is | Reduces ambiguity |
| Comparison table | Shows similar metrics side by side | Supports faster decision-making |
| External citation | Points to a trusted reference | Improves verification and confidence |
Frequently Asked Questions
Who writes the educational content on this site?
Jack Shi, an independent developer and the founder of Clooms, builds and maintains the site, including the calculator engine, the worked examples and the guides.
What is the mission of the site?
The mission is to make statistical analysis more understandable, easier to verify, and easier to apply in practical work. A calculator is only useful when the surrounding explanations help users choose the right formula and interpret the output correctly.
Why include external references on an about page?
Because the site is built around measurable concepts. Linking authoritative definitions of standard deviation, variance, and statistical methods helps users assess the educational standard behind the product.