Seam Allowance Converter
Got a Burda pattern with no seam allowance? Need to convert from US ⅝" to French ½"? Select your current and target seam allowances and get exact instructions for adding or trimming — edge by edge.
Current seam allowance (what the pattern has)
Target seam allowance (what you want)
Add ⅝" per seam edge
Converting from 0" → ⅝"
How to do it
- 1Trace each pattern piece onto fresh paper, or work directly on tissue paper pieces.
- 2On every seam edge, measure outward from the existing cutting line by ⅝" and mark.
- 3Connect the marks with a smooth line parallel to the original cutting line. For straight seams, a ruler; for curves, use a curved ruler or walk a tape measure.
- 4Trim the tissue to the new cutting line. The seamline (original cutting line) is now the stitching line — do not remove it.
- 5Repeat for every seam edge on every pattern piece. Do not add to hemlines unless converting hem allowance as well.
Curved seams
On curved seams (neckline, armhole, crotch curve), the new cutting line must follow the curve — don't just extend straight. After sewing, clip or notch the curved SA so it lies flat.
Corners & points
At corners and points (collar tips, waistband corners), the added SA will overlap. Mark accurately to the corner point, then trim diagonally across the corner after sewing.
Common brand standards
Burda Style
None (0)
Always add your own before cutting.
Big 4 (US)
⅝" (1.5 cm)
Simplicity, McCall's, Butterick, Vogue.
Closet Core
½" (1.3 cm)
Clearly marked on pattern pieces.
True Bias
½" (1.3 cm)
Included; noted on pieces.
Seamwork
⅝" (1.5 cm)
US standard.
Cashmerette
⅝" (1.5 cm)
US standard.
Named Clothing
1.5 cm (⅝")
European metric standard.
Papercut Collective
1 cm (⅜")
Verify on individual pattern.
Always check the individual pattern's instructions — some patterns within a brand deviate from the standard. Seam allowances are usually noted on the first instruction page or on the pattern pieces themselves.
Seam allowance tools
Adjustable slider for marking consistent seam allowances
Amazon→Better than pins for curves and thick fabrics
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