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.
About this Pattern Size Grading Calculator
Use this free Pattern Size Grading Calculator to get quick, accurate results directly in your browser. It is designed for everyday use with no signup, no downloads, and no account required. No signup is required, and the tool works on phones, tablets, and desktop browsers.