Can I enter only the highest and lowest readings?

No, enter all five recorded readings. A range alone does not determine the sample standard deviation or the actual measurement mean.

Do identical readings prove perfect precision?

No, the observed deviation is zero, but limited instrument resolution can conceal variation. Review the scale resolution before accepting that result.

Should I compare the mean with a master?

Use a separate bias assessment with a qualified reference. This page estimates repeated-reading spread, which does not establish measurement accuracy.

Can different operators supply these five readings?

No, hold the operator and method fixed for this repeatability check. Between-operator changes belong in a reproducibility study.

Quality & Metrology calculator

Gauge Repeatability Calculator

Check the short-run spread of five repeat measurements. Keep the same part, operator, gauge and method, then enter your maximum permitted sample standard deviation.

What this calculator does

Estimate short-run repeatability from five actual readings of one stable part under unchanged conditions.

Formula used

Mean = sum of five readings ÷ 5
Sample standard deviation = sqrt(sum((reading − mean)²) ÷ 4)
Observed range = maximum reading − minimum reading
Limit margin = maximum allowed deviation − sample standard deviation

Inputs explained

Reading 1: Actual repeat reading with the same operator, gauge and part.
Reading 2: Actual repeat reading with the same operator, gauge and part.
Reading 3: Actual repeat reading with the same operator, gauge and part.
Reading 4: Actual repeat reading with the same operator, gauge and part.
Reading 5: Actual repeat reading with the same operator, gauge and part.
Maximum Repeatability Deviation: Permitted sample standard deviation from your measurement plan.

How to use the result

Best suited to Short-Run gauge Check, fixture repeatability trial.
Five readings give only four degrees of freedom and an imprecise estimate. This check excludes operator, part, long-term drift and bias effects.

Current U.S. benchmarks

U.S. manufacturing runs at 75.7% of capacity (Federal Reserve, Aug 2026). New factory orders are up 8.5% year over year (Census).

Common questions

Can I enter only the highest and lowest readings? No, enter all five recorded readings. A range alone does not determine the sample standard deviation or the actual measurement mean.
Do identical readings prove perfect precision? No, the observed deviation is zero, but limited instrument resolution can conceal variation. Review the scale resolution before accepting that result.
Should I compare the mean with a master? Use a separate bias assessment with a qualified reference. This page estimates repeated-reading spread, which does not establish measurement accuracy.
Can different operators supply these five readings? No, hold the operator and method fixed for this repeatability check. Between-operator changes belong in a reproducibility study.

Last reviewed 2026-10-06.