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How to sew a hem that hangs straight

A hem is two folds and a straight line. What makes it look bought rather than home-made is measuring once and pressing twice.

Turn under 5 mm and press. Turn again to your hem depth, using a seam gauge so every point around the garment matches, and press again. Pin from the fold side. Sew from the right side if you want a visible topstitch, from the wrong side if you want to follow the fold edge exactly. The gauge is what makes this repeatable — measuring with a tape at each pin introduces a drift you will see at the front hem.

Questions people actually ask

How deep should a hem be?

On a straight skirt or trouser, 30 to 40 mm gives weight and hangs well. On a curve, go narrower — 10 to 15 mm — because a deep hem on a curve has more fabric on the outer edge than the inner and will not lie flat.

Why does my hem ripple?

Usually a deep hem on a curved edge, or stretching the fabric as you feed it. Ease the fabric rather than pulling it, and reduce the hem depth on anything shaped.

Last reviewed 2026-08-11