Any Size Long Johns from Wool Sweaters

Recycle an old sweater into toasty wool long johns.
By Nikol Lohr
Cotton thermals and space age synthetic long underwear are all well and good, but nothing kills the winter chills like a pair of old fashioned, toasty wool long johns. Trouble is, despite improvements in softness well known to knitters, wool still has a bad rap among the general population for itchiness. So despite the prevalence of cottony-soft merino, wool long johns have fallen out of favor. Not only are they hard to find, but at around 50 bucks a pop, they’re hard to justify. But fret not! Real wool long johns can be yours for the price of a thrift store wool sweater and about an hour at the sewing machine. If you get lucky and score a cashmere sweater, you’re really in for a treat!
Recycled long johns are cheap, eco-friendly, community-conscious (supporting local thrift stores), and can be made in interesting colors or stitch patterns, depending on what you find on the sweater rack. You can make them thicker (read: warmer) than the typical off-the-shelf counterpart, and you can get a custom fit. While they’re not as streamlined as their store-bought brethren, you’re probably wearing them to bed or under layers, so what’s a few extra seams between friends?
If you’ve got kids to dress, the recycled long johns are especially fun, because you’re more likely to find Fair Isle options in the smaller sizes on the thrift store rack.

Materials

Soft wool sweater See Step 1 notes.
1 yd no-roll elastic, or 2 yards drawstring material grosgrain ribbon, twill tape, etc.
Large safety pin
Seam ripper for cuffed version
2 large plastic beads (optional) for drawstring
Fine yarn for darning holes or applying appliqués
Pins
Scissors
Sewing machine
Thread
Download the PDF
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Directions

Step 1: Find the right sweater.
Shape (Adults): Crew necks and turtlenecks are preferable, because they take up less room and you’ll be using a portion of the chest for your leg. Avoid V-necks and scoop necks. Look for a straight shoulder instead of a fitted sleeve. Lay the sweater flat and look at the shape. The arms should extend straight out from the collar to the cuff. Don’t choose a sweater with fitted, inset sleeves that curve down at the shoulder, unless your whole leg fits in the sleeve. Kids/babies: In most cases, you won’t need to extend the leg past the sleeve, so a curved shoulder is fine.
Size: Choose a sweater a couple sizes up from your normal sweater size. Make baby long johns from little kid sweaters, little kid long johns from big kid sweaters, big kid long johns from small adult sweaters, small adult long johns from large adult sweaters, and larger adult long johns from adult plus size sweaters. For growing kids, you can make a size or two up and fold up the cuffs, as the kids in the picture are wearing. The family picture shows long johns made from an extra large men’s sweater (on the woman), a medium men’s sweater (on the toddler, with several inches of growing room), and a small child’s sweater (on a baby, with several inches of growing room).
To test whether your sweater will work for long johns, you’ll have to try it on. Holding the sweater upside down, and treating the bottom hem as the waist, stick your leg into the sleeve with the collar facing your crotch. The sleeve should be snug but not tight (not putting pressure) around your leg. If you’ve got a straight-shouldered sweater, the collar of the shirt should reach to your crotch. If the shoulder is curved, the armpit should reach your crotch.
Fiber: Look for soft wool (merino is an easy bet) or cashmere in a fine gauge. Remember that 100% wool is great, but blends are good, too; 30%-50% wool makes an excellent warm garment that’s often easier to care for. If you’ve got angora or alpaca in the mix, as little as 20% will be toasty. Be sure to pick something soft enough for your bare skin, unless you’re planning to layer. Avoid thick hand-knits — anything over DK weight will be too bulky to seam. If you find something machine-washable, hurrah! All the better.
Color/Pattern: Fair Isle, cables, etc., will work as long as you have a fine gauge. Otherwise, there are too many ends and textures to potentially cause problems when you’re cutting and sewing.
Other Features: Look for sweaters with few or no holes. A handful of holes can be quickly darned or patched, but you don’t want to add hours to your quickie project. Contrast cuffs and hems can be fun.
Step 2: Wash.
If washing is going to change the garment, you want that to happen before you get started. If you have a wool/hand wash cycle on your machine, you can wash the sweater in a quick cycle with a cold water rinse. Otherwise, soak undisturbed, in hot, soapy water, for 20 minutes. Rinse, squeeze out excess water, and let dry. (Personally, I machine-wash all my woolens, including my hand knits, so if it can’t take a round on the wool cycle, I want to know before I get started.)

Step 3: Make legs from the sleeves (see cutting diagram below).
Before you get to work on your seat, decide whether you want your casing to fold in, toward your body, or out, like a cuff. If you have a nice ribbed hem, folding out looks good. If you’re folding the waist casing in, you can seam your sides all the way to the top from the wrong side (right sides facing). If you’re folding it out, you’ll want to seam only until the point where you’ll fold it. Jump ahead and check out Step 7 if this is unclear!


Adults: Cut straight across about ½” down from the pits and right across the body. Using a stretch stitch, zigzag, or serge, sew cut the edges shut, right in line with the sleeve seams (in this example, that’s a ½” allowance, but you’ll be trimming it to run flush with the sleeve if you’ve got a serger). Fold the tube in half and cut directly down the middle of the collar to make 2 legs. Then trim at an angle to get rid of the collar. Try on the sleeve/legs. The taller side (cut edge) should orient to the outside of your thigh. If they’re really baggy, take both legs in along the inseam before you continue.
Kids: Simply cut the sleeves off before the shoulder seams. If the sweater has a fitted, inset shoulder, make the cut before shaping.
Step 4: Make a seat from the body of the sweater.
Lay out the sweater’s body, imagining the hem as your waistline. Overlap both legs, with the inseam flush with the cut side of the body. If your sweater is too wide, you’ll want to trim and seam one side before you continue.
Note: if you’re planning a fold-over waistline, only sew up to the area you want to fold (in this case, we’ll seam the ribbing in the opposite direction).
Place the tops of the legs over your seat so you have a sort of panty-shaped overlap, then mark with chalk, making sure the distance from the waist to the leg is equal on both sides before cutting. Trim the front side angles only so they’re about an inch shorter than the back angles.

Step 5: Attach the legs to the seat.
Turn the legs right side out, slip them inside the inside out body, and pin the legs evenly to the body, right sides facing. The high/pointy side of the leg will line up with the side seam of the panty. Sew the legs to the body using a stretch stitch, zigzag, or serge and a ½” seam allowance.

Step 6: Tailor the front panel.
Note: You can skip this step if you’re making long johns for a baby, leaving extra room for the diaper.
Turn the long johns inside out and lay them flat. Pull up a flap down the front center, as shown. For a woman, start with a flap 3″ deep; for a man, try 2″. For kids’ sizes, try 1″-2″, depending on the size. Mark a line with chalk along the fold. It will taper from the waist to the crotch. Pin running parallel along the line, and try them on. If the fit seems good (best to err on the side of too loose, especially if you’re serging), reorient the pins for sewing and seam along the line; otherwise, adjust it in or out for a good fit and try on again before sewing. Remember, you’ve still got to add the elastic to the waist. This is just to fit the front of the long johns so they’re not all dumpy and baggy. If you’ve used a sewing machine, trim the excess after seaming.
Note: if you’re planning a fold-over waistline, only sew up to the area you want to fold (e.g., the ribbing).

Optional: For a smooth, reinforced, finished edge without a serger, press your seams open and secure them with a zigzag stitch. Carefully trim the excess fabric close to your zigzag stitch with sharp scissors.

Step 7: Make the waist casing.
You can choose between a casing that folds in (smooth exterior) or out (cuffed exterior). If you choose the cuffed version, you can use a drawstring instead of elastic (you can also do a drawstring with the smooth version, but you’ll need to make a buttonhole or grommet, which isn’t covered here).
Before you get started, mend any holes that will fall on your casing.
Fold in the casing (smooth exterior). All of your seams should extend all the way to the waistline. Fold over and steam-press the waist edge ½” more than the width of your elastic. Seam ¼” from the edge, leaving a 1½” gap to insert the elastic.

Fold out the casing (cuffed exterior). Your seams should stop at or just beyond the ribbing. Using a seam ripper or sharp scissors, remove any original seams down to the ribbing so all seams are open where the cuff will be. Seam the open ends with the wrong sides facing (opposite of the other seams). If you’re using a drawstring, leave a ½” gap near what will be your new top edge. If you have a factory or serged edge, leave it as-is. If you have a raw edge around your hole, turn it under (towards the right side, along with the cuff seams). Steam-press the ribbing and seam ¼” from the edge, leaving a 1½” gap if you’re using elastic.

Step 8: Insert the elastic or drawstring.
For an elastic waist, cut the elastic 2″ shorter than your actual waist for adults, or 1″ shorter for children. With a large safety pin to help nudge it along, feed the elastic through the casing. Make sure the elastic hasn’t twisted in the casing, then overlap the elastic ends by ¾” – 1″ and sew together. Sew down the gap in the casing.
For drawstrings, cut the drawstring 2″-3″ longer than your waist measurement (use shorter length for kids’ drawstrings). Use a large safety pin to help you feed the drawstring through the casing and back out the hole. If you like, slip a bead onto each end and knot to keep the bead in place. This will make it easy to feed the drawstring back through if it accidentally gets lost in the casing.

Step 9: Mend any holes.
Using fine yarn and a needle or sweater scraps, darn any holes and/or sew on appliqués to cover them. I used hearts cut from scraps of both sweaters to cover mended holes and make coordinating long johns for two sisters.

Thanks to mom Sherri and daughters Kyplee and Kailynn for modeling!
Download the PDF
(Right click to save the file to your desktop. See directions.)
About the Author:

Nikol Lohr lives at The Harveyville Project with her partner, 2 cats, 7 sheep, and 7 hens. She’s the author of Naughty Needles & founder of Yarn School. She blogs at The Thrifty Knitter, is cupcake on Ravelry, and queenievonsugarpants on Flickr.