๐Ÿ“ Quality Tool  ยท  Avg & Range  ยท  ANOVA Method

Gauge R&R Calculator

Enter measurement data โ€” get %GRR, NDC, variance components & measurement system acceptability instantly

1
Analysis Method & Configuration
Choose method
Average & Range Classical MSA method
ANOVA Method Interaction term included
2
Measurement Data
10 parts ร— 3 operators ร— 2 reps
Gauge R&R Analysis Result
Average & Range Method
LIVE
โœ…
Measurement System Acceptable
%GRR < 10% โ€” System is capable for production use
%GRR (of Tolerance)
โ€”
%
%Repeatability (EV)
โ€”
%
%Reproducibility (AV)
โ€”
%
NDC
โ€”
categories
%GRR (Tolerance-based) โ€”%
โ€”
โ‰ค10% Acceptable 10โ€“30% Marginal >30% Unacceptable
Variance Contribution (% of Total)
Gauge R&R (GRR)
โ€”
Repeatability (EV)
โ€”
Reproducibility (AV)
โ€”
Part Variation (PV)
โ€”
Repeatability (EV)
ฯƒ_repeatabilityโ€”
EV (kร—ฯƒ)โ€”
% of Toleranceโ€”
Rฬ„ (avg range)โ€”
Reproducibility (AV)
ฯƒ_reproducibilityโ€”
AV (kร—ฯƒ)โ€”
% of Toleranceโ€”
Xฬ„_diff (op range)โ€”
Part Variation (PV)
ฯƒ_partsโ€”
PV (kร—ฯƒ)โ€”
% of Toleranceโ€”
Rp (part range)โ€”
โ€”
%GRR Acceptance Criteria (AIAG MSA): โ‰ค10% โ€” Acceptable. 10โ€“30% โ€” May be acceptable depending on application. >30% โ€” Measurement system needs improvement.
NDC (Number of Distinct Categories): Should be โ‰ฅ5 for the gauge to meaningfully distinguish parts.

Why I Built This Gauge R&R Calculator

Gauge R&R studies always come up when you are trying to validate a measurement system before a new production launch or when a process is producing parts that are borderline on spec and you need to know whether the problem is the process or the gauge. Doing it by hand with the AIAG MSA manual open is manageable once you know the formulas, but it is the kind of calculation where one transposed number in the range table sends everything wrong.

The Average and Range method is the standard approach most people use on the shop floor because it is straightforward and does not need software. ANOVA gives you more information by separating out the operator-by-part interaction term, which matters when certain operators consistently read certain parts differently from others.

I built this to handle both methods, take the raw measurement data in a table you can fill in directly, and immediately show the %GRR breakdown, variance components, NDC, and whether the measurement system passes the AIAG acceptance criteria. No spreadsheet, no manual lookup of d2 constants.

Part of TaskJunction โ€” free engineering calculators. No login, no signup, just tools that work.

โ€” Vaibhav Dhokpande, Developer ยท TaskJunction