Waistband Calculator
A fitted waistband is cut longer than your waist for ease and closure overlap, and doubled in width to fold over.
Why the waistband is longer than your waist
Beyond your waist measurement, the band needs ease to sit comfortably and an overlap at the closure end so a button or hook & bar has somewhere to fasten to — without that overlap, the band would meet edge-to-edge with no way to close.
Cutting the width for a fold-over waistband
Most sewn waistbands are cut as one long strip that folds in half lengthwise: one long edge attaches to the garment, the other folds under and gets stitched or topstitched down. That means the cut width needs to be double the finished band height, plus seam allowance on both long edges.
Interfacing keeps a waistband from rolling
Fusible interfacing on at least one layer of the band is what gives a waistband its crisp, structured stand rather than a soft, rolling edge — apply it to the wrong side before folding and stitching the band together.