Sewing Pattern Size Chart: Choose the Right Size From Your Measurements
Sewing pattern sizes have nothing to do with ready-to-wear clothing sizes. A store size 8 is NOT a pattern size 8. This is the single most common mistake that ruins sewing projects. This guide explains how to read pattern size charts, choose the right size from your measurements, and blend between sizes for a perfect fit.
Pattern Sizing vs Ready-to-Wear: The Difference
| Pattern Sizes (Big Four) | Ready-to-Wear Sizes | |
|---|---|---|
| Based on | Standardized body measurements from the 1940s | Vanity sizing (varies by brand) |
| A size 12 means | 34" bust, 26.5" waist, 36" hip | Varies wildly by brand |
| Ease included | Yes — wearing ease + design ease | Minimal standard |
| Changes over time | Almost none | Constantly (vanity sizing) |
Pattern companies haven't changed their size charts in decades. Your pattern size is likely 2-4 sizes larger than your store-bought size. This is normal. Ignore the number. Use your measurements.
How to Choose Your Pattern Size
- Measure your bust, waist, and hips using the body measurement guide
- Look at the pattern envelope's size chart (NOT your ready-to-wear size)
- Choose the size that matches your LARGEST measurement
- If you span multiple sizes, buy the larger one — you can take in but can't let out
For dresses and tops: Use your bust measurement as primary. For pants and skirts: Use your hip measurement as primary.
Blending Between Sizes
Most bodies don't match one pattern size perfectly. If your bust is a size 14 and your hips are a size 12, you blend:
- Trace the size 14 from shoulder to waist
- Gradually transition to size 12 from waist to hip
- Use a French curve to smooth the transition line
This is called "grading between sizes" and it's the #1 skill that separates homemade-looking garments from professional fit.
Understanding Ease
Patterns include two types of ease:
- Wearing ease: Minimum extra fabric needed to move and breathe (typically 2-3" at bust)
- Design ease: Extra fabric for style — a fitted dress has less, an oversized coat has more
The finished garment measurements are printed on the pattern tissue. Compare these to your body measurements to understand how the garment will fit.
👉 How to Measure for Sewing — Complete body measurement guide 👉 Clothing Size Calculator — US/UK/EU size conversion 👉 Body Type Calculator — Know your shape before choosing patterns