Sewing pajama bottoms is a beginner-friendly project that takes about two to three hours

Pajama bottoms are one of the easiest garments to sew because they have no closures, no collar, and no fitted sleeves. You need only a straight stitch, two seams, and a casing for the elastic waistband. The finished pair will fit better and cost less than store-bought versions, and you can choose your own fabric and length.

This guide walks you through measuring, cutting, sewing the inseams and side seams, and threading elastic through the waistband. You will use a sewing machine, scissors, elastic, and thread—all standard supplies. Even if you have never sewn before, the steps are straightforward enough that mistakes are hard to make.

Key Takeaways

  • Measure your inseam (inside of your leg from crotch to ankle) and your waist, then add 1 inch to the waist measurement for the casing seam allowance.
  • Cut two identical pant legs from your fabric, then sew the inseams first, then sew the side seams to join the legs together.
  • Fold the top edge down 1.5 inches and sew a casing all the way around, leaving a 2-inch opening to thread the elastic through.
  • Thread 0.5-inch-wide elastic through the casing, overlap the ends by 0.5 inches, sew them together, then sew the opening closed.
  • Fold the leg openings up 0.5 inches twice and sew a hem, or leave them raw if your fabric does not fray.

Take your measurements and prepare your pattern

You need two measurements: your inseam and your waist. For the inseam, stand in bare feet and measure from your crotch straight down to your ankle bone on the inside of your leg. Write this number down. For the waist, measure around your natural waist where the elastic will sit, not your hip bone.

Once you have both numbers, add 1 inch to your waist measurement (this becomes your casing seam allowance) and add 1 inch to your inseam (this is for the hem). These are your cutting dimensions. For example, if your inseam is 28 inches and your waist is 30 inches, you will cut pant legs that are 29 inches long and 31 inches wide.

You do not need a commercial pattern. Draw a straightforward rectangle on paper using your measurements, then cut it out. This is your template. You will use it twice—once for each pant leg.

Cut your fabric and prepare the pieces

Fold your fabric in half lengthwise, with the right side (the side you want showing) facing inward. Lay your paper template on the folded fabric and pin it down. Cut around the template with sharp scissors or a rotary cutter, cutting through both layers at once. When you unfold the fabric, you will have two identical rectangles.

Before you sew, check that the edges are straight and that both pieces are the same size. If one is slightly smaller, trim the larger one to match. Lay both pieces flat on your work surface with the right sides facing each other (so the wrong sides are facing out). This is the position you will sew from.

Sew the inseams and side seams

The inseam is the seam that runs down the inside of your leg. With the right sides of your fabric still facing each other, align the two long edges of one rectangle. Pin them together every 3 to 4 inches. Set your sewing machine to a straight stitch with a stitch length of 2.5 millimeters. Sew down the pinned edge, starting at the top and stopping at the bottom. Use a 0.5-inch seam allowance (the distance between the edge of the fabric and your stitching line). Backstitch at the start and end to lock the thread.

You now have a tube. Turn it inside out so the right side of the fabric is facing outward. Press the inseam flat with an iron. Repeat this process with the second rectangle to create a second tube.

Now sew the side seams. Lay one tube inside the other, right sides facing each other, so the inseams line up. Pin the two long edges together. Sew down both edges with a 0.5-inch seam allowance, starting at the top and sewing all the way to the bottom of each leg. Backstitch at the start and end. Turn the whole piece inside out so the right side is facing outward. You now have a complete pant leg with two seams.

Create the waistband casing and thread the elastic

Fold the top edge of the pant leg down 1.5 inches toward the inside, with the wrong side of the fabric facing outward. Pin this fold all the way around. Sew a straight line 1 inch from the top edge, creating a tunnel (called a casing) that runs all the way around the waist. Stop sewing 2 inches before you reach your starting point and backstitch. This 2-inch opening is where you will thread the elastic through.

Cut a piece of 0.5-inch-wide elastic to a length that is 1 inch shorter than your waist measurement. For example, if your waist is 30 inches, cut the elastic to 29 inches. Attach a safety pin to one end of the elastic and feed it through the casing opening, working it all the way around the tunnel until both ends of the elastic come out of the opening.

Overlap the two ends of the elastic by 0.5 inches and sew them together with a small rectangle of stitching (sew back and forth three times over the overlap to make it strong). Push the joined elastic back into the casing. Sew the 2-inch opening closed with a straight stitch, backstitching at the start and end.

Hem the leg openings

Fold the bottom edge of each pant leg up 0.5 inches toward the inside, with the wrong side of the fabric facing outward. Press this fold flat with an iron. Fold it up another 0.5 inches and press again. Pin the fold all the way around and sew a straight line close to the inner fold, backstitching at the start and end. Repeat for the other leg.

If your fabric is a knit (like jersey or fleece) or does not fray easily, you can skip hemming and leave the leg openings raw. Knits do not unravel the way woven fabrics do, so a raw edge will not come apart in the wash.

Common mistakes to avoid

The most common error is sewing with the wrong sides of the fabric facing each other. Always check before you start sewing that the right sides (the sides you want to see when you wear the pajamas) are facing inward. If you sew with the wrong sides facing each other, your seams will be on the outside of the finished garment.

Another mistake is making the casing too narrow. If you fold the top down less than 1.5 inches, the elastic will bunch and the casing will be hard to sew. If you fold it down more than 2 inches, the waistband will be too loose and uncomfortable. Stick to 1.5 inches.

A third mistake is threading the elastic too tightly. If you pull the elastic taut as you thread it through the casing, the waistband will be uncomfortably tight when you wear the pajamas. Let the elastic sit naturally in the casing without pulling it.

Frequently Asked Questions

What fabric should I use for pajama bottoms?

Cotton flannel, cotton jersey, fleece, and linen are all good choices. Flannel is warm and soft, jersey is stretchy and comfortable, fleece is cozy, and linen is breathable for warm weather. Avoid stiff fabrics like denim or canvas—they are uncomfortable to sleep in. Buy 1.5 to 2 yards of fabric, depending on your inseam length.

Do I need a serger or overlock machine?

No. A basic sewing machine with a straight stitch is all you need. Sergers are useful for finishing seams so they do not fray, but they are not necessary for pajama bottoms. Your seams will be inside the garment where they will not show.

Can I make pajama bottoms without elastic?

Yes, but you will need a drawstring instead. Skip the casing and sew the waistband closed. Then poke a hole on each side of the waistband and thread a drawstring through. Tie the drawstring at the front to adjust the fit. This takes a few extra steps but works well if you prefer drawstrings.

How do I know if my seam allowance is correct?

Most sewing machines have a line marked 0.5 inches from the needle. Align the edge of your fabric with that line as you sew. If your machine does not have a marked line, use a piece of tape on the machine bed 0.5 inches from the needle as a guide.

What thread should I use?

All-purpose polyester thread works for any fabric. Match the thread color to your fabric if possible, but neutral colors like black, white, or gray work on most fabrics. Use the same thread color in both the top and bobbin of your machine.