COMPARE / TRANSPARENT METHOD

Z-score from a dataset

Express distance from the mean in standard deviation units.

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Details ↗
This tab’s workspace

Optional sessionStorage, off by default. Keeps text, table and settings across tools and languages in this tab. Browser session restoration can retain it. Use “Delete saved data” on a shared device. Nothing is uploaded.

Temporary storage is off unless you select the option.

Interactive examples

Predefined synthetic data only. The link shares the example, never your numbers or metadata. Loading an example replaces current fields.

01Enter your data

Example
Dataset type
Analysis name and unit (optional)

Report labels only, not conversions. Variance uses squared units; z-score is dimensionless.

Paste numbers or one Excel column. Thousands separators are not supported.

x is not added to the dataset. We use the decimal mark selected above.

⇧ Import or paste a table

Choose options explicitly. Missing cells are flagged, not skipped.

Download an example CSV ↓
Review the table before importing

Uses the columns and decimal format selected above. Row numbers refer to the parsed table including the header; completely blank rows may already have been ignored. No correction or exclusion is automatic.

At most 80 notices are displayed; every row is checked.

Compare table columns

Select up to 8 numeric columns. Every selected cell must be valid; no individual missing values are removed. This is a descriptive comparison, not a test between groups.

Select columns
Resume an analysis from a file

Open a .json file exported by StatNivo. Replaces current data and recalculates in this calculator; nothing is uploaded.

Raw data: up to 10,000 values per series.

Temporary storage is off unless you select the option.

02Read your result

Loading the local calculator…
Export, save and share

Undefined values: empty cells. No additional rounding in CSV files. CSV headings use stable English identifiers for software compatibility.

Temporary storage is off unless you select the option. Optional sessionStorage, off by default. Keeps text, table and settings across tools and languages in this tab. Browser session restoration can retain it. Use “Delete saved data” on a shared device. Nothing is uploaded.

UNDERSTAND, DON’T JUST CALCULATE

The method in practice

Methodology and sources ↗
z = (x − reference mean) / standard deviation

The dataset is your reference

This tool derives mean and standard deviation from the observations you enter. The value x is compared against that reference and is not automatically added to it. Sample or population mode changes the standard deviation used in the denominator.

A checkable example

For 2, 4, 4, 4, 5, 5, 7, 9 in population mode, the mean is 5 and standard deviation is 2. For x = 7, z = (7 − 5)/2 = 1: one standard deviation above the mean.

Not a significance test

A positive score is above the reference mean and a negative score below it. We do not convert scores to probabilities or assume normality. If the reference has zero spread, the ratio is undefined.

Practical checks before using a result

Sample or population?

For 2, 4, 4, 4, 5, 5, 7, 9 the population SD is 2; sample SD is √(32/7) ≈ 2.13809. Choose the population formula when describing the full population of interest, not because the number is smaller.

Standard deviation or standard error?

Standard deviation describes the spread of observations. The usual standard error of the mean is sample SD / √n under independent sampling with finite variance. For sample SD 10 and n = 25, SEM = 2. Repeated dependent readings do not automatically count as 25 independent measurements.

Importing from Excel without shifting pairs

Paste the entire table, select its real delimiter and header, then preview it. In decimal-comma data, use a semicolon or tab as the column delimiter. If Y is missing in row 3, fix that row rather than moving row 4 up.