Usually yes, but not always. Most commercial envelope patterns and most indie PDF patterns include seam allowances in the cut line. Some patterns leave them out, including many Japanese pattern books, some drafting-style patterns, and a few specialty designs. Check the instructions for your pattern before you cut.
How to tell for sure
- Look for a stated measurement. The instructions or the pattern piece itself often say something like "5/8 in (1.5 cm) seam allowance included." Our guide to reading pattern instructions, symbols and markings covers where to find this.
- Look for a stitching line. A dashed line inside the cut edge usually means the allowance is included. If there is only one outline, read the notes carefully.
- Check the hem. Hem allowances are often handled separately from side and armhole seams, so confirm each one.
What you can generally expect
| Pattern type | Seam allowance usually included? | What to confirm |
|---|---|---|
| Commercial envelope patterns | Typically yes | The stated width, and whether it varies by seam |
| Indie PDF patterns | Often yes, but the width varies | The width, since it may differ from envelope patterns |
| Japanese pattern books | Often no | You may need to trace and add your own |
| Drafting or draping books | Often no | The instructions for adding allowances |
These are tendencies, not rules. The pattern in your hands is what counts.
If it's not included
Trace the pattern and add the allowance around each edge. A clear ruler or a seam guide makes this far less fiddly. Allow extra fabric too, because the added width can change your yardage. Our fabric requirements guide explains how to estimate it.
A tradeoff worth knowing
Included allowances save time, but they make fit changes a little fussier, because you have to work around them. Patterns without allowances give you flexibility to choose your own width, such as a narrower one for curves, but you take on extra tracing work and a bigger chance of uneven edges. Neither is better. It depends on how you like to work.
If you adjust patterns often, our reviewed fitting tools and books may help. Confirm current details on each official site before buying.