SPC
Xbar-R Chart Calculator
Upload subgrouped CSV data or use example data to calculate Xbar-R chart center lines and control limits.
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Upload CSV or Use Example Subgroup Data
Each row is one subgroup. Use one numeric column per observation within the subgroup.
Interpretation
Xbar-R charts are commonly used for small subgroup sizes where ranges are a practical estimate of within-subgroup variation.
UCLx̄ = x̄̄ + A₂R̄