Button Spacing Calculator

The buttonhole at bust level should always be horizontal. A horizontal buttonhole resists the pull of fabric across the fullest part of the bust — the button slides to the end of the slit and locks in place, preventing the placket from pulling open.

All other buttonholes should be vertical, aligned along the center front line. Vertical buttonholes keep the button precisely on center front and look cleaner on areas that don't experience significant lateral pull.

On men's shirts and garments without bust shaping, all buttonholes are typically vertical. On women's button-front blouses, shirts, and dresses, the horizontal-at-bust rule is standard.

The most common complaint with button-front garments is gapping at the bust. This happens when no button falls at the fullest point of the bust — fabric between the two nearest buttons pulls apart, exposing the layer underneath. A button placed exactly at bust level eliminates this gap.

If your pattern's even spacing doesn't place a button at bust level, you have two options: shift the spacing slightly (this calculator does that for you), or add a snap or hook-and-eye closure between buttons at bust level as a hidden reinforcement.

For coats, jackets, and garments with heavy interfacing (also called interlining or Vilene), sew a small flat backing button on the wrong side, directly behind the main button. This distributes the stress across a wider area and prevents the fashion button from pulling through the fabric over time.

Create a thread shankbetween the button and the fabric (wrap thread around the base 6–8 times under the button) for garments thicker than a single layer. The shank gives room for the buttonhole layer to sit between the button and the garment without puckering.

Always interface the placket area before stitching buttonholes. Use your machine's buttonhole foot and stitch a test buttonhole on a scrap of the same fabric + interfacing sandwich.

To cut open: place a pin across one end of the buttonhole (this stops the blade from cutting through the bar tack), then cut from the center toward each end with a sharp seam ripper or rotary buttonhole chisel. A chisel on a cutting mat gives the cleanest result.

Apply a tiny dot of fray check to the cut edges if your fabric is prone to fraying — let it dry completely before testing the button through the hole.