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Pattern & Sizing Calculators

Pattern grading, ease calculations, and body measurement adjustments for perfect fit.

10 free calculators in Pattern & Sizing

Getting the Right Fit from Sewing Patterns

Sewing pattern sizes differ from ready-to-wear sizes. Pattern companies use standardised body measurements, so a size 14 pattern may not match a size 14 from the high street. The key is to measure your body accurately — bust, waist, hip and back length — and choose the pattern size that best matches your measurements.

Ease is the difference between your body measurement and the finished garment measurement. Wearing ease (typically 5–8cm at the bust) allows for movement and comfort. Design ease adds extra fullness for style — a fitted blouse has minimal design ease, while an oversized coat may have 15cm+ of extra ease.

When your measurements fall between sizes or differ from standard proportions, you need to adjust the pattern. A Full Bust Adjustment (FBA) adds volume at the bust without altering the rest of the bodice. Similarly, hip and waist adjustments modify the lower body while keeping the overall fit. Pattern grading moves all edges of a pattern proportionally to create a different size.