Gage R&R Calculator
Calculate Gage Repeatability and Reproducibility percentage and number of distinct categories (NDC).
How to Use the Gage R&R Calculator
- Enter repeatability and reproducibility standard deviations.
- Enter part variation standard deviation.
- Click Calculate to see %GRR, NDC, and assessment.
使用场景
- •Measurement system analysis (MSA).
- •AIAG MSA studies for IATF 16949.
- •Validating measurement tools before SPC.
公式
Formula: %GRR = σ_measurement / σ_total × 100. NDC = 1.41 × (Part Variation / GRR σ).
常见问题
What is Gage R&R?
Gage R&R quantifies measurement system variation from both repeatability (same operator, same part) and reproducibility (different operators).
What %GRR is acceptable?
Below 10% is acceptable, 10–30% is marginal (may be acceptable depending on use), above 30% is unacceptable.
What is NDC?
Number of Distinct Categories — how many groups of parts the measurement system can distinguish. NDC ≥ 5 is required for process control.