Knit Hem Calculator
Choose your hem method, select your fabric weight, and get the exact allowance, machine settings, and step-by-step instructions. No more wavy hems.
Units:
Twin Needle Hem
intermediate1.25"
Hem allowance to add
1"
Finished hem width
Steps
- 1.Fold the hem up 1" to the wrong side and press.
- 2.Use Wash-Away Wonder Tape or fabric glue stick to hold the fold (pins cause ripples).
- 3.From the right side, stitch with a twin needle. The two rows should be close to the fold edge.
- 4.Trim the excess fabric on the inside close to the stitching.
Machine settings
- -Twin needle spacing: 3.0mm (light) or 4.0mm (medium)
- -Stitch length: 3.0-3.5mm (longer than regular sewing)
- -Upper tension: reduce by 1-2 numbers from normal
- -Use a stretch or ballpoint needle in the twin
- -Bobbin: regular thread (the bobbin automatically zigzags)
Equipment needed: Twin needle (3.0mm or 4.0mm) — fits most standard sewing machines
Tips
- -The #1 cause of wavy twin needle hems is stretching the fabric while sewing. Use a walking foot.
- -Reduce the presser foot pressure if your machine allows it.
- -Sew slowly. Speed causes more stretching on knits.
- -Test on a scrap first — every knit fabric behaves differently.
- -If the hem still waves, try using lightweight fusible interfacing (interlining/Vilene) on the hem allowance before folding.
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