# Garment Size Grade Calculator

> Grade one garment measurement from the base size across a size range using your grade increments, with separate grades below and above the base.

Category: Textile & apparel · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/garment-size-grade-calculator

Grading adds a fixed increment for each size above the base and subtracts one for each size below. Enter the base measurement and your grade rule to get the full size spec.

Also called: Pattern grading calculator, Grade rule calculator.

## Inputs
- Size labels, smallest to largest (default XS, S, M, L, XL, XXL)
- Base (sample) size (default M)
- Base size measurement (default 100)
- Grade per size below the base (default 4)
- Grade per size above the base (default 5)

## Results
- Graded measurements
- Smallest size
- Largest size
- Spread across the range

## Formula

```
Size k below base: M − k × Grade down;  size k above base: M + k × Grade up
```

Where:
- M: base size measurement
- k: number of sizes away from the base
- Grade: increment between neighbouring sizes

## Worked example
1. Below M: S = 100 − 4 = 96; XS = 100 − 2 × 4 = 92.
2. Above M: L = 100 + 5 = 105; XL = 110; XXL = 115.
3. Spread = 115 − 92 = 23.

**Result:** A 100 cm chest at size M grades to 92, 96, 100, 105, 110 and 115 cm from XS to XXL.

## What the result means

Use it for one point of measure at a time (chest, waist, length). Body length, sleeve length and width usually have different grades.

## Assumptions and limits
- Grading is linear: the same increment for every size step on each side of the base.
- Grade rules are brand- and market-specific; enter your own. Pattern-point grading on CAD distributes the increment across several points.

## Questions

### Why have a different grade above and below?

Many brands use a larger jump for bigger sizes (for example 4 cm below and 5–6 cm above) so larger sizes fit better.

### Can I use numeric sizes?

Yes. Enter labels such as 36, 38, 40, 42 and pick one as the base.

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- [Fabric Consumption per Garment Calculator](https://calculators.geekmidst.com/calculators/fabric-consumption-per-garment-calculator)
- [Length Converter](https://calculators.geekmidst.com/calculators/length-converter)

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/garment-size-grade-calculator