Size Run Calculator
Calculate quantity per size using a bell curve distribution for apparel production planning.
Inputs
Results
Units at Peak Size
172
How to Use This Calculator
- Enter Total Units — the total production run quantity.
- Set Number of Sizes in your size range.
- Enter Peak Size Position — which size (by rank) sells the most (typically the middle size).
- Adjust Curve Spread to control how steeply the bell curve drops off toward extremes.
- Review Units at Peak Size, Smallest Size Units, Total Allocated, and Rounding Waste to finalize the production size ratio.
How the result changes with Total Units
| Total Units | Units at Peak Size |
|---|---|
| 10,009 | 3,437 |
| 35,007 | 12,021 |
| 65,004 | 22,324 |
| 90,001 | 30,907 |
What each input means
- Total Units
- Total production quantity across all sizes.
- Number of Sizes
- How many sizes in your range (e.g., XS-XL = 5 sizes).
- Peak Size Position
- Which size gets the most units (1 = smallest, n = largest). Usually medium.
- Curve Spread
- 1 = tight (heavy on peak size), 2 = normal distribution, 3 = wide (more even spread).
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersTotal Units = 500, Number of Sizes = 5, Peak Size Position = 3, Curve Spread = 2 = 4 input(s) provided
- Calculate Units at Peak SizeUnits at Peak Size172 = 172
- Calculate Smallest Size UnitsSmallest Size Units43 = 43
- Calculate Total AllocatedTotal Allocated500 = 500
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators.
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