Statistics

Variance Calculator

Calculate variance. Free online Variance Calculator. Calculate variance online — fast, accurate, mobile-friendly, no signup needed.

Variance (sample)
4.571429

Derivation

  1. ├── 01Givenlist = 2, 4, 4, 4, 5, 5, 7, 9
  2. ├── 02Formulaa.reduce((e,t)=>e+(t-n)²,0) / (a.length-1)
  3. └── 03Compute Variance (sample)4.571429
Did you know?

The arithmetic mean goes back to Babylon; the median was formalised by Gustav Fechner (1874); "mode" was coined by Karl Pearson in 1895.

§01What is

Understanding the Variance Calculator

The Variance Calculator computes Variance (sample) from 1 input: comma-separated numbers. Calculate variance.

Statistics is how we make sense of noisy real-world data. Whether you’re analysing survey results, sports scores, or business metrics, a statistics calculator gives you the exact formula-based answer so you can focus on the interpretation. The Variance Calculator sits in that toolkit — it calculate variance. Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.

§02The Formula

How it’s calculated

a.reduce((e,t)=>e+(t-n)²,0) / (a.length-1)

Where

list
Comma-separated numbers
§03Practical Example

Step-by-step walkthrough

Scenario

Apply the formula to a realistic set of inputs: Comma-separated numbers = 2, 4, 4, 4, 5, 5, 7, 9.

  1. 01Start by noting the input — Comma-separated numbers: 2, 4, 4, 4, 5, 5, 7, 9.
  2. 02Substitute these values into the formula: a.reduce((e,t)=>e+(t-n)²,0) / (a.length-1)
  3. 03Compute Variance (sample): the calculator returns 4.57143.
  4. 04Cross-check the answer by opening the Derivation panel above — every line of math is shown so you can follow the computation end-to-end.
§04FAQ

Frequently asked questions

Yes. The calculator implements the standard formula as documented and returns exact floating-point results. No approximations are used unless noted in the formula.
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