Replicate Statistics

Summarize one group of measurements, with the sample size, spread and exclusions visible beside the result.

Calculated in this tabUser-assigned unitsNo automatic data storage

01 · Your measurements

Use measurements of the same quantity in the same unit. Each accepted record counts once. Decide which observations are independent before interpreting SEM.

Open a CSV, TSV or text file

UTF-8 text, up to 256 KiB, 2,000 records including any header, 100 columns and 20,000 cells. The file is read locally into the editable text area.

Measurement data

Record format / delimiter

Decimal mark

Choose the delimiter explicitly. Decimal comma requires semicolon, tab or one value per line; comma CSV uses decimal points. Scientific notation is accepted. Thousands separators and formulas are not. A final newline ends a record; blank lines within the data are reported as missing.

Measurement column (1–100)

Measurement unit

Assign the unit used by every measurement; enter 1 for dimensionless values. This labels the result and does not convert data.

Treat the first record as a header

Calculate CV: I confirm a ratio scale with a meaningful zero

For example, length or mass. Celsius and Fahrenheit temperatures do not qualify. This tool also requires nonnegative values and a positive mean.

Paste data or select a file, assign units, then calculate.

I reviewed the listed records and allow their exclusion

Changing data or settings resets this choice. Calculate again after confirming.

02 · Your result

Arithmetic mean

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SD describes variation among observations. SEM estimates the sampling precision of the mean under independence assumptions. It is not an individual-measurement spread or a confidence interval.

No current result. Nothing is uploaded or saved automatically.

Exports include accepted measurements, assigned units, method and excluded line numbers/reasons. Keep your original file if you need the rejected text or unused columns.

Method & interpretation

Formulas and sample size

mean = Σx / n
sample SD = √[Σ(x − mean)² / (n − 1)]
SEM = sample SD / √n
CV (%) = 100 × sample SD / mean

For the synthetic measurements 10, 12 and 14, n = 3, mean = 12, sample SD = 2 and SEM ≈ 1.154700538. With only one measurement, mean and min/max are available; sample SD, SEM and CV are not.

All observations have equal weight. Independent observations from the same population with finite variance are needed to interpret SEM as an estimate of sampling precision. Repeated readings from one specimen do not automatically increase the number of independent specimens. This tool does not check independence or normality, combine groups, remove outliers or calculate confidence intervals.

Data handling, CV and limitations

Only the selected column is summarized. Other columns are not included in exported results. Missing values, nonnumeric entries and inconsistent row widths are listed by starting line number. Nothing is excluded without your choice. A header is skipped only when selected. Broken CSV quoting rejects the complete input.

CV is optional and requires a meaningful zero. It is unavailable for a nonpositive mean or negative measurements in this tool; a mean near zero can make CV unstable. Assigning a unit does not prove that this condition is met.

Accepted numbers use browser floating-point arithmetic; extremely small values that underflow to zero and nonfinite results are rejected. Keep the original measurement precision and inspect unusual values. Outputs are descriptive calculations, not a validation of experimental design or standards compliance.

Technical sources

Alkoc Labs calculation engine v0.6.0. References support the method; they do not imply endorsement.

Keep the calculation context.

Download a work package to retain the reviewed inputs and results. Open it in Workspace to combine results. For figures, use Graph Studio and label error bars as SD or SEM according to your intended meaning.

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