How to Sew a Beanie-Style Helmet Liner From a T-Shirt

  • 01 of 08

    Sew a Beanie-Style Hat to Protect Your Head and Hair

    Sew a Helmet Liner From a T-Shirt
    The Spruce / Mollie Johanson

    Why buy a helmet liner when you can make one out of a t-shirt? This beanie-style cap protects your head and hair under a motorcycle or bike helmet, a hard hat, or even as an extra layer under another hat. You could even wear it on its own!

    By using a t-shirt, you can make this helmet liner cap in a flash. You don't even need a serger, because the t-shirt creates the finished hem of the hat.

    Plus, with a few simple measurements, it's easy to make this in any size you need, no matter who's hopping on a bike.

    Continue to 2 of 8 below.
  • 02 of 08

    Helmet Liner Materials

    Transform a T-Shirt Into a Beanie
    The Spruce / Mollie Johanson

    Supplies and Tools

    • T-shirt
    • Tape measure
    • Rotary cutting tools
    • Pins
    • Sewing machine
    • Basic paper plate (or another 9 1/4 inch circle template)

    Note: Instead of a t-shirt, you can use other knit fabric, but you will need to do a bit more finishing for the hem.

    Continue to 3 of 8 below.
  • 03 of 08

    Measure and Cut the T-Shirt

    Cut a Rectangle at the Hem
    The Spruce / Mollie Johanson

    First, measure the head of the person who will wear the helmet liner. Measure around from the forehead to the top of the neck. Add 1/2 inch to the measurement. This average-size hat starts with a 24-inch measurement.

    Cut a piece 8 inches wide and the length of the head measurement from the bottom of the t-shirt so that the hem is the bottom of the long edge.

    The easiest way to do this is to lay the shirt flat, cutting the piece on the fold to half the head measurement. 

    Knit fabrics, especially pre-washed t-shirts, often have a little twist. If you find this in the shirt you're using don't worry, as it won't affect things.

    Continue to 4 of 8 below.
  • 04 of 08

    Sew the First Seam

    Sew the Rectangle Into a Tube
    The Spruce / Mollie Johanson

    Sew the rectangle into a tube with a french seam for a strong finished seam.

    To do this, fold the rectangle and match the short edges with the wrong sides together. Pin the fabric and sew along the short edge with a scant 1/4-inch seam allowance.

    Continue to 5 of 8 below.
  • 05 of 08

    Finish the Back Seam of the Hat

    Finish the Seam at the Back of the Hat
    The Spruce / Mollie Johanson

    Turn the tube wrong side out. Pin and sew the seam again, with a 1/4-inch seam allowance (or slightly larger if needed to encompass the first seam). 

    If possible, check that the tube fits the wearer's head.

    Lay the tube flat with the seam centered. 

    Continue to 6 of 8 below.
  • 06 of 08

    Mark and Cut the Shaping

    Cut Curves at the Top of the Hat
    The Spruce / Mollie Johanson

    Fold a large paper plate in quarters. You can also start with a paper circle template or a dinner plate that's at least 9 inches in diameter.

    Use the folded plate to cut curves on each side of the tube.

    Continue to 7 of 8 below.
  • 07 of 08

    Sew the Curved Top of the Helmet Liner

    Sew the Curves on the Hat
    The Spruce / Mollie Johanson

    Pin the curves and top edge. Sew the top of the hat together with a 1/4-inch seam allowance. Back stitch at the beginning and end, making sure that the sewing reaches the edges of the folded sides.

    Turn the hat right side out.

    Continue to 8 of 8 below.
  • 08 of 08

    Wear the Helmet Liner and Get Ready to Ride

    DIY Beanie From a T-Shirt
    The Spruce / Mollie Johanson

    Tips and Ideas

    • Instead of a close-fit helmet liner, make this into a slouchy beanie by cutting the initial rectangle to 10 inches tall or more.
    • For a snugger fit, use a larger circle template. 
    • All-over print t-shirts make great caps with lots of decoration.
    • For a warmer helmet liner, make this out of anti-pill fleece and hem the bottom.