What is the standard seam allowance for commercial patterns?

• A. 5/8 inch
• B. 1/4 inch
• C. 3/8 inch
• D. 1/2 inch

Answer: (A)

The standard seam allowance is 5/8 inch. Seam allowance is the extra fabric between the stitching line and the raw edge, giving you room to sew, finish the edge, and still have fabric to size or alter later. For most woven fabrics used in garment sewing, pattern makers choose 5/8 inch because it provides a sturdy seam, accommodates typical fabric shrinkage after washing, and leaves enough room for a clean finish without wasting too much material. Commercial patterns are drafted with this margin so you can sew pieces together with a consistent, reliable seam width across different patterns. If you’re working with knits or special finishes, you might see smaller allowances or different methods, but the common default for regular woven garments is 5/8 inch.