Skip to content
Get in touch

A clearer view of your numbers

Measurement Repeatability & Statistics Calculator

Summarize repeated measurements with a mean, sample deviation and standard uncertainty of the mean.

Browser-local calculations · No login · No financial values sent

Your inputs

01 / Enter

These are editable examples, not recommended rates. Enter your own numbers.

Calculator inputs

Enter 1–1,000 decimal measurements separated by spaces, newlines, commas or semicolons. Use a dot decimal; commas separate observations, not thousands or decimal digits. Each absolute value must be at most 1 trillion.

All measurements use this same unit. Changing the label does not convert input values.

Your result

02 / Understand

Loading the example calculation…

Show the math

Calculations retain numerical precision. Displayed quantities are rounded to significant digits, not to cents.

What this means

Sample standard deviation describes scatter of individual repeated measurements. Dividing that deviation by the square root of the count estimates standard uncertainty of the mean under the stated repeatability assumptions.

Worked example

For 1, 2, 3, 4, 5 units: n=5, mean=3, minimum=1, maximum=5, range=4, sample standard deviation=√2.5 ≈1.58113883, and standard uncertainty of the mean=√0.5 ≈0.70710678 units.

How the math works

Mean = Σx/n; range = maximum−minimum. Sample standard deviation s = √[Σ(x−mean)²/(n−1)]. Standard uncertainty of the mean u = s/√n. Shifted, compensated two-pass arithmetic reduces numerical cancellation around large offsets.

About this estimate

At least two observations are required for s and u; one still gives count, mean, min, max and range. Repeats should represent the same quantity under the same conditions and be independent for s/√n. Neither independence nor normality is tested. Reference uncertainty, bias, resolution and other Type B terms are excluded; this is not a complete uncertainty budget.

Reference conventions

Keep working through it

Related calculators for the next question.

Calibration & Metrology

Calibration Error & Correction Calculator

Compare an instrument indication with a reference and distinguish signed error from additive correction.

Open calculator Calibration & Metrology

Instrument Accuracy Specification Calculator

Interpret a stated percentage or count specification using an explicit single-term or additive convention.

Open calculator Calibration & Metrology

4–20 mA Signal Scaling Calculator

Convert current and engineering values in either direction across a linear 4–20 mA span.

Open calculator

Need a different calculation? Suggest a calculator.

Formula v1.0.0 · Reviewed · Tool ID: measurement-repeatability