Size sewing patterns by taking accurate bust, waist, and hip measurements with a flexible tape measure. Compare these to the pattern’s size chart, not store sizing. Use finished garment measurements printed on the pattern tissue to check fit, adjusting pattern lines as needed for accuracy.
Sewing pattern size calculator
Taking accurate measurements is the foundation of successful pattern sizing. Unlike buying ready-to-wear clothing where you might guess your size, sewing requires precision to achieve that perfect fit.
Required measuring tools
For accurate body measurements, you’ll need just a few basic items. First, a flexible measuring tape that’s soft and no wider than 1 cm is essential—metal construction tapes won’t work for body measurements. Additionally, gather a pen and paper to record your numbers, and position yourself in front of a full-length mirror. While having someone help is beneficial, you can take most measurements yourself with proper mirror positioning. For marking reference points, a narrow elastic band or string can be incredibly helpful.
Step-by-step measuring process
Before beginning, wear minimal clothing—ideally just undergarments or close-fitting clothes. When measuring:
- Stand in a neutral position with back straight, shoulders relaxed, chin up, and arms hanging naturally at your sides
- For circumference measurements, keep the tape parallel to the floor
- Hold the measuring tape snug against your body, but not too tight
- Start with your waist as a reference point for other measurements
- For women, wear a well-fitting, unpadded bra when measuring your bust
Recording your measurements effectively
Most patterns require three fundamental measurements: bust, waist, and hip. However, recording additional measurements provides better fitting options. Create a measurement reference chart where you can note:
- Bust: Measure around the fullest part, often at nipple level
- Waist: Measure the smallest part of your torso, typically above your belly button
- Hips: Measure the widest part around your bottom
- Shoulder width: From neck meeting point to shoulder edge
- Arm length: From shoulder bone to wrist
Decoding Pattern Size Charts
Pattern size charts often confuse even experienced sewists. Primarily, this happens because sewing pattern sizes are not standardized across companies. Forget what size you wear in ready-to-wear clothing—a size 12 in one pattern could be entirely different in another.
Understanding size ranges and categories
Pattern companies create their designs based on specific “blocks” (standard templates) that they then grade up and down to create size ranges. Many patterns include designations like “Misses,” “Women’s,” or “Plus Size” with each category using different proportions. Most Misses patterns are designed for a B cup with a 2-2.5″ difference between bust and high bust measurement, while Women’s patterns often accommodate a C cup with different proportions.
Finding your size when measurements span multiple sizes
Most sewists discover their measurements fall across different sizes—this is completely normal. For a fitted dress, select size based on your high bust measurement if you’re using patterns designed for B cups. For skirts and pants, the hip measurement typically determines your size. When your measurements span sizes, you can “grade” between them by:
- Drawing smooth transition lines between sizes on pattern pieces
- Checking that intersecting pieces (waistbands, facings) align properly
- Adding equal amounts to both front and back pieces when adjusting
Resizing Patterns for Perfect Fit
Rarely does anyone fit perfectly into a standard pattern size. After taking measurements and analyzing pattern charts, I’ve found that resizing patterns is often the crucial next step for achieving that perfect fit.
The slash and spread method for sizing up
The slash and spread method is the most reliable technique for enlarging patterns. To size up a bodice, I start by tracing the original onto sturdy paper, then make strategic cuts. For proper proportion, I cut through the center of the underarm, shoulder, and neckline/bust. When adding width, it’s important to distribute it correctly—adding nothing to the shoulder split for sizes 12 to 14, but instead adding 1/4″ to both the bust split and underarm split. Most women need more room in the bust area, not the shoulders.
Techniques for sizing down patterns
When sizing down, I use the same fundamental approach but in reverse. Instead of spreading the pattern pieces apart, I overlap them. For a bodice decreased by 1/4″, I place the bottom piece securely, then overlap the side pieces by 1/8″ on each side. The key is maintaining the pattern’s proportions while reducing its overall size. For children’s patterns, I need to slash both vertically and horizontally since adult armholes would be far too large.
Grading between sizes for proportional fit
Almost no one falls perfectly into one size category. When my measurements span different sizes—perhaps a size 10 waist with size 14 hips—I grade between them. I draw a smooth line between the notches at different points, ensuring the same changes appear on all pieces. This works effectively for up to three sizes difference; beyond that requires careful curve management and a test garment.
Digital tools for pattern resizing
Digital pattern manipulation offers precision advantages. PDF patterns can be resized during printing using Adobe Reader’s “Custom Scale” option. For more complex adjustments, specialized software like Pattern Maker or Wild Ginger provides professional-grade tools.
When using projector sewing technology, I can digitally add or subtract height by moving pattern images up/down or left/right. These digital methods eliminate the need for physical cutting and taping, though seam allowances will scale proportionally with the pattern.
Conclusion
Learning how to size sewing patterns correctly transforms your sewing journey from frustrating to fulfilling. Throughout this guide, we’ve explored the essential elements of achieving that perfect fit for your handmade garments.
Taking accurate measurements serves as the foundation of successful pattern sizing. Your body’s unique proportions rarely match standard pattern sizes exactly, which explains why most sewists find their measurements spanning multiple sizes. This reality, though initially confusing, simply reflects our wonderfully diverse body shapes.
Pattern size charts often bewilder even experienced sewists due to their lack of standardization across companies. Remember, your ready-to-wear clothing size means little when selecting pattern sizes. Instead, focus on finished garment measurements and ease allowances for truly comfortable, well-fitting clothes.
