Sewing Your Own?
Get the Band Length Right.
Home-sewn bras need a precise band pattern length, accounting for negative ease (how much smaller than your body the elastic band should be) and seam allowance. Enter your underbust measurement and preferences to get a cutting length.
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- ✓ Adjustable negative ease and seam allowance
Calculate your pattern band length
Enter your underbust measurement and sewing preferences.
Why Negative Ease Matters
Bra bands are cut smaller than the body measurement on purpose, since the fabric and elastic need to stretch to fit snugly and do the actual supporting. Most home-sewing patterns use 8-15% negative ease depending on the fabric's stretch percentage stretchier power mesh can use more negative ease, while less stretchy fabrics need less. Always add seam allowance on top of the eased measurement, and cut a test band in scrap fabric before committing to your good fabric.
Frequently Asked Questions
What negative ease percentage should I use?
Check your fabric's stretch most bra-making patterns recommend 8-15%, with stretchier power mesh nearer the top of that range.
Do I need seam allowance on both ends of the band?
Yes this calculator adds it once per side, so double the seam allowance value if you want the total added across both cut edges.
Should I make a test (muslin) version first?
Strongly recommended band elastic and fabric behave differently once sewn, so a test version in cheap fabric saves your good materials.