Pattern Size Grading Calculator
Calculate grading differences between a pattern size and your target measurements.
Note: Professional pattern grading is complex and varies by garment type and designer. This tool provides a basic estimate suitable for simple patterns and small size adjustments only.
Measurement
Pattern Size (inches)
Your Measurement (inches)
Bust / Chest
Waist
Hip
Shoulder Width (optional)
Back Length (optional)
Standard Size Chart Reference
| Size | Bust | Waist | Hip |
|---|---|---|---|
| XS (2–4) | 31–32" | 23–24" | 33–34" |
| S (6–8) | 33–34" | 25–26" | 35–36" |
| M (10–12) | 35–36" | 27–28" | 37–38" |
| L (14–16) | 37–40" | 29–32" | 39–42" |
| XL (18–20) | 41–44" | 33–36" | 43–46" |
| 2XL (22–24) | 45–48" | 37–40" | 47–50" |
| 3XL (26–28) | 49–52" | 41–44" | 51–54" |
How to Use the Pattern Grading Calculator
- Enter the measurements listed on the pattern envelope or instructions (the "pattern size") in the middle column.
- Enter your own body measurements in the right column.
- Shoulder width and back length are optional but help with more accurate grading.
- Click Calculate Grading to see the difference at each point and how much to add or remove.
Understanding the Results
- Total Diff — How many inches larger (+) or smaller (−) your measurement is compared to the pattern.
- Per Side — For circumference measurements (bust/waist/hip), the adjustment is spread across the sides of the pattern. Divide by 4 for a standard front-and-back 2-piece pattern (each seam gets ¼ of the adjustment).
- For length measurements (back length), the total difference is added or removed at a single point.
Important Limitations
- This calculator gives a simple linear estimate. True pattern grading curves seam lines and shifts design elements proportionally.
- Always make a test garment (muslin or toile) before cutting expensive fabric.
- For differences larger than 2 sizes (4"), consider buying the nearest size and doing a full adjustment rather than grading.