How to Set a Sewing Machine Seam Guide for Accurate Seam Allowances

Close-Up Of Textile Being Stitched In Sewing Machine
Iuliia Safronova / EyeEm / Getty Images

After accurately cutting out a pattern, the easiest way to assure that pattern pieces will fit together is to make sure your seam allowances are accurate. Teaching yourself to watch a seam guide and not the moving sewing machine needle will help maintain consistent seams allowances.

What You'll Need

Equipment / Tools

  • Tape measure
  • Sewing machine
  • Seam guide
  • Sewing gauge


  1. Use the Tape Measure

    Place the machine needle down on the mark on the tape measure. Place the presser foot down on the tape measure, making sure you have the tape measure straight by lining up the other markings on the tape measure with the side of the presser foot.

    lining up the tape measure on the sewing machine
    The Spruce / Debbie Colgrove
  2. Set the Seam Gauge

    Place your seam guide at the end of the tape measure, making sure it is perpendicular to the end of the tape measure. Do not make your seam guide longer than you need it to line the fabric up as it passes under the sewing machine needle.

    Place the seam gauge at the end of the tape measure.
    The Spruce / Debbie Colgrove
  3. Set Your Seam Guide for Sewing Curves

    When you are sewing curves, it is essential to have a turning point that is directly horizontal to the machine needle. To set this point, set the sewing gauge directly behind the needle, setting the end of the gauge even with the edge of the seam guide. Draw a line along the edge of the gauge. The mark at the edge of the seam guide is where you need to line up the fabric as you sew a curve.

    Setting a seam guide for curved seams
    The Spruce / Debbie Colgrove