Pajama pants are pull-on trousers with a straight or wide leg, a relaxed fit, an elastic waist and usually no pockets, sewn in a soft washable fabric such as cotton flannel, lawn, poplin or double gauze. From a pull-on trouser pattern they take four leg pieces, about 2.4 m (2 5/8 yd) of 140 cm (55 in) wide fabric and 1 m (1 1/8 yd) of 3 cm (1 1/4 in) elastic, and they sew in about two hours: side seams, inseams, crotch seam, casing, hem. Pre-wash the fabric hot first, because flannel and gauze shrink more than most cottons.
What do you need to sew pajama pants?
The pieces, from an elastic-waist trouser pattern:
- Front leg, cut twice as a mirrored pair, with the casing folded from the top edge.
- Back leg, cut twice as a mirrored pair.
- Pocket bags, cut four, only if you want in-seam pockets.
Notions: 3 cm wide elastic, your waist measurement minus 5 to 8 cm (2 to 3 1/8 in); polyester or cotton thread; a universal needle in 80/12 for flannel and poplin or 70/10 for lawn and gauze; a safety pin or bodkin to thread the elastic.
Fabric on 140 cm wide fabric: 2.2 to 2.6 m (2 3/8 to 2 7/8 yd) for full-length straight legs on an adult, 2.6 to 3 m (2 7/8 to 3 1/4 yd) for a wide leg. Many flannels and lawns are 110 cm (45 in) wide: add 0.4 to 0.6 m (1/2 to 5/8 yd), and more again for a plaid you want to match at the side seams. The fabric yardage calculator converts between widths.
Which fabric is best for pajama pants?
| Fabric | Season | Weight | Notes |
|---|---|---|---|
| Cotton flannel | Winter | 150 to 200 gsm (4 1/2 to 6 oz) | Shrinks noticeably, has a nap, frays |
| Cotton lawn | Summer | 60 to 90 gsm | Cool, smooth, needs a fine needle |
| Cotton poplin | All year | 100 to 130 gsm | Crisp, easy to cut and press |
| Double gauze | Summer | 120 to 150 gsm | Airy, shrinks a lot, shifts when cut |
| Seersucker | Summer | 90 to 120 gsm | Never needs ironing |
| Washed linen | All year | 150 to 200 gsm | Softens with every wash |
Flannel is the pajama fabric most people reach for first, and it has two habits to plan for: it shrinks by several centimeters per meter in the first hot wash, and its brushed surface has a nap, so every piece must be cut with the top in the same direction or one leg looks darker. Sewing with flannel covers both.
Which pattern options make good pajamas?
A straight leg in a relaxed fit is the classic pajama; a wide leg is cooler in summer and suits lawn and gauze. Full length to the ankle bone, or ankle length with 2 to 3 cm (3/4 to 1 1/4 in) of clearance from the floor so the hem does not get stepped on. Keep the elastic at 3 to 4 cm wide: narrower rolls, wider digs in when you lie on your side. Skip the pockets, or keep in-seam ones for a pair you will wear around the house.
The one measurement that decides comfort is the seated crotch depth, taken sitting on a hard chair from the waist down to the seat. Pajamas need the full depth plus 2 to 3 cm of ease so they do not pull when you curl up. Crotch depth is not the same as crotch length, the front-to-back measurement through the legs; it is the depth that sets where the waist sits.
How do you sew pajama pants, step by step?
- Pre-wash and press. Wash and dry the fabric at the temperature you will use for the pajamas, then press. Cut with the nap running down on all four pieces. For a plaid, place the same bar on the hem line of the front and back legs so it matches at the side seams.
- Choose a seam. For a soft inside that touches skin, sew French seams: wrong sides together at 0.6 cm (1/4 in), trim to 3 mm, press, then right sides together at 0.9 cm (3/8 in), which uses the full 1.5 cm (5/8 in) allowance. Otherwise sew at 1.5 cm and finish with a zigzag or a serger.
- Sew the side seams, right sides together (or wrong sides first for a French seam), matching the plaid. Press toward the back.
- Sew the inseams of each leg from the hem to the crotch point. Press toward the back.
- Sew the crotch seam. Turn one leg right side out and slip it inside the other, right sides together, matching the inseams and the center front and back. Sew the curve in one pass from front waist to back waist, then sew the lower curve a second time 2 mm inside the first. This seam takes the most strain of the whole garment. Clip the curve and press the allowances to one side.
- Make the casing. Press the top edge under by 1 cm (3/8 in), then fold it down 4 cm (1 5/8 in) and press. Stitch close to the inner fold, leaving a 5 cm (2 in) gap at the center back. Thread the elastic with a safety pin, keeping it flat, overlap the ends by 2 cm and zigzag them in a square, ease the join into the casing and close the gap. Stitch in the ditch of the side seams and the center seams through the casing so the elastic stays put in the wash.
- Hem with a double fold, 1 cm then 3 cm (3/8 then 1 1/4 in), stitched close to the inner fold. A deep hem suits flannel, which frays, and adds a little weight so the legs hang straight.
- Press, lightly on flannel so the nap is not crushed.
How tight should the elastic be?
Cut it at your waist measurement minus 5 to 8 cm and pin the ends together, then try the pants on sitting and lying down before you sew the join. For sleeping, err on the loose side: the elastic has to hold the pants up when you stand, nothing more. Firm braided elastic narrows as it stretches and feels tighter than it measures; knitted or woven elastic keeps its width and is softer for pajamas. The elastic length calculator gives a starting length from your waist and the elastic type.
What are the most common mistakes with pajama pants?
- Skipping the pre-wash. Flannel pajamas that fit on Monday are ankle-grazers after the first hot wash.
- Nap in two directions. One leg looks darker. Lay all four pieces with the top the same way.
- Twisted elastic. It twists inside the casing. Keep it flat with the safety pin, and stitch in the ditch at the seams.
- One line of stitching on the crotch seam. Sew it twice; it is the seam that splits.
- A narrow hem on flannel. It frays through. Use 3 cm or more.
- Elastic at the waist measurement. The pants slide down in the night. Cut it shorter and pin-fit.
Can Sewly draft the pajama pants for you?
Sewly's pull-on trousers pattern is drafted from your waist, hip and seated crotch depth, with a wide, straight, tapered or jogger leg, a regular, relaxed or oversized fit, full or ankle length, an elastic width from 1 to 5 cm, and in-seam pockets, patch pockets or none. The sewing guide works out the elastic length for your waist and the fabric quantity for 110, 140 and 150 cm wide fabric, with a cutting layout, which is useful for a 110 cm flannel.