Measure your dog before you choose a pattern
A dog jumper that fits depends on three measurements taken with a soft tape measure while your dog stands still. Measure the length from the base of the neck to the base of the tail — this is the back length. Measure around the widest part of the chest, just behind the front legs. Measure around the neck where a collar normally sits. Write these down in inches or centimetres and keep them handy when you look at patterns.
Most knitting patterns for dog jumpers are sized by back length — small (8–10 inches), medium (12–14 inches), large (16–18 inches) — and the pattern will tell you the finished chest measurement. If your dog's chest is larger than the pattern allows, you may need to add extra stitches or choose a larger size and shorten the back length instead. A jumper that is too loose will slip; one that is too tight will restrict movement and cause discomfort.
Take photos of your measurements written down. If you set the project aside and return to it weeks later, you will have the numbers without having to measure again.
Key Takeaways
- Measure your dog's back length, chest, and neck with a soft tape measure before selecting a pattern, because sizing varies between patterns and a poor fit will either slip or restrict movement.
- Most dog jumper patterns use worsted or aran weight yarn and require between 400 and 800 yards depending on the dog's size, so check the pattern's yardage before you buy.
- Cast on using the long-tail method, knit the body in stockinette stitch or ribbed stitch, and shape the neck and armholes by decreasing stitches at marked points in the pattern.
- Seaming the underside with mattress stitch creates a flat, invisible seam that is more comfortable against your dog's skin than a visible ridge.
- Wash the finished jumper in lukewarm water with wool wash, lay it flat to dry, and check the fit on your dog before weaving in any remaining ends.
Choose yarn weight and yardage based on your dog's size
Dog jumpers are usually knitted in worsted weight (medium weight, often labelled as weight 4) or aran weight (heavier, weight 5). Worsted weight is easier to work with and gives a lighter jumper suitable for most indoor dogs or mild weather. Aran weight knits faster and produces a thicker, warmer fabric for outdoor dogs or cold climates.
The yardage you need depends on the pattern and your dog's size. A small dog jumper typically requires 400–500 yards; a medium jumper needs 500–700 yards; a large jumper may need 700–900 yards. Always check the pattern's yardage requirement before you buy yarn, because running short partway through means unpicking and starting over or leaving the jumper unfinished. Buy one extra ball if you are uncertain — leftover yarn can be used for a matching collar or donated.
Choose yarn in a colour that suits your dog's coat and hides dirt. Darker colours show less wear and staining than light colours. If your dog has sensitive skin, pick a yarn labelled as soft or superwash-treated, which is gentler than rough fibres and easier to wash.
Cast on and knit the body in stockinette or ribbed stitch
Most dog jumper patterns begin with a ribbed cuff at the neck. Cast on the number of stitches specified in your pattern using the long-tail cast-on method, which creates an elastic edge that stretches slightly when your dog pulls the jumper over its head. Knit 1, purl 1 for 1 to 2 inches to create the ribbed neck cuff, then switch to the main stitch pattern — usually stockinette stitch (knit on the right side, purl on the wrong side) or ribbed stitch throughout.
Knit straight up the back until you reach the armhole depth marked in your pattern. This is usually 2 to 4 inches depending on your dog's size. At the armhole, you will begin decreasing stitches to shape the opening for the front legs. The pattern will tell you exactly where and how many to decrease — typically you bind off 2 to 4 stitches at the start of each row for one or two rows, then decrease one stitch at the edge every other row until the armhole is the right width.
Continue knitting the body straight up until you reach the length specified in your pattern. This is where your initial measurement of back length matters most. If the pattern says the finished back length is 12 inches and your dog measures 13 inches, add one extra inch of knitting before you bind off. Bind off all stitches loosely so the edge does not pucker.
Shape the neck and armholes with decreases
After you bind off the back, you will pick up stitches around the neck opening and the two armholes to knit the ribbed edging that finishes those openings. Use a smaller needle size than you used for the body — usually two sizes smaller — so the ribbing is tight and does not stretch out of shape.
Pick up stitches by inserting your needle under the bumps along the edge of the knitted fabric and pulling yarn through to create new stitches. For the neck, pick up roughly one stitch for every stitch you cast on, plus a few extra at the corners. For each armhole, pick up stitches around the entire opening — front, back, and underarm. Knit 1, purl 1 ribbing for 1 to 2 inches, then bind off. This ribbing should feel snug but not tight enough to restrict your dog's breathing or movement.
If your pattern includes shaping at the chest or sides, you will decrease stitches as you knit the body rather than waiting until the armhole. Follow the pattern's decrease instructions exactly — they are placed to create a shape that tapers at the waist and widens at the chest, which keeps the jumper from sliding backward.
Seam the underside with mattress stitch for comfort
Once all pieces are knitted, you will seam the underside of the jumper from the armpit to the tail using mattress stitch, which creates an invisible seam by weaving yarn through the bumps on the edges of the knitted fabric. This seam lies flat against your dog's skin and is much more comfortable than a visible ridge or a seam that puckers.
Thread a tapestry needle with a length of yarn matching your jumper. Starting at one armpit, insert the needle under the first bump on one side, then under the corresponding bump on the other side, moving up the seam in a zigzag pattern. Pull the yarn snug every few stitches so the seam closes invisibly. Work all the way down to the tail, then fasten off by weaving the end through the last few stitches and trimming.
If your pattern includes a seam at the underside of each leg (from armpit to the edge of the armhole opening), seam those the same way. Check that all seams lie flat and that no bumps or ridges stick up, because these will irritate your dog's skin when it moves.
Weave in ends and wash before the first wear
After seaming, you will have yarn ends at the cast-on edge, the bind-off edge, and anywhere you joined new yarn. Thread each end through a tapestry needle and weave it through the bumps of nearby stitches for about 2 inches, then trim close to the fabric. Weave ends along seams rather than across the body, so they do not show if the jumper stretches.
Before your dog wears the jumper, wash it in lukewarm water with wool wash or a gentle detergent. Soak for 10 to 15 minutes, rinse gently in clean water until the water runs clear, then squeeze out excess water without wringing. Lay the jumper flat on a clean towel to dry, reshaping it to the measurements in your pattern as it dries. This first wash removes any oils or dust from the yarn and helps the fibres settle into their final shape.
Once the jumper is completely dry, put it on your dog and check the fit. The back should lie flat without bunching, the neck should be snug but not tight, and the armholes should allow full movement of the front legs. If the fit is wrong, you can still unravel and reknit before weaving in the ends permanently.
Adjust pattern sizing if your dog is between sizes
If your dog's measurements fall between two pattern sizes, you have two options. The first is to knit the smaller size and add extra length to the back — this works well if your dog is longer than average but not wider. The second is to knit the larger size and shorten the back length, which works if your dog is wider than average but shorter. Never ignore the chest measurement, because a jumper that is too tight will restrict breathing and movement, and one that is too loose will slip backward when your dog walks.
You can also modify the pattern by adding or subtracting stitches at the cast-on edge. If the pattern calls for 48 stitches and your dog's chest is one inch larger than the pattern allows, add 4 stitches (roughly one stitch per inch of circumference). Work the extra stitches into the ribbing and the main body evenly so the shaping stays balanced. Write down any changes you make so you can repeat them if you knit another jumper for the same dog.
Frequently Asked Questions
What if my dog won't sit still while I measure?
Measure while your dog is standing or sitting naturally, not stretched out. If your dog moves, take the measurement again. You need accuracy more than speed — a jumper that does not fit will be uncomfortable and your dog will refuse to wear it. If your dog is very restless, ask another person to hold it still while you measure.
Can I use acrylic yarn instead of wool?
Yes, acrylic yarn works and is often cheaper and easier to wash. Acrylic does not stretch as much as wool, so the jumper may feel stiffer and less comfortable. It also does not regulate temperature as well, so your dog may overheat indoors. Acrylic is a good choice for outdoor dogs in cold weather or if your dog has a wool allergy.
How do I know if the armholes are the right size?
The armhole should be large enough that your dog's front leg moves freely without the jumper pulling at the shoulder or armpit. When your dog walks, the jumper should not ride up or twist sideways. If the armhole is too small, your dog will struggle to move and may refuse to wear the jumper. If it is too large, the jumper will slip backward. Test the fit before you seam the underside, so you can adjust if needed.
How often should I wash a dog jumper?
Wash the jumper every two to four weeks, or more often if your dog spends time outdoors or has dirty paws. Use lukewarm water and wool wash, soak gently, and lay flat to dry. Avoid the washing machine and dryer, which will felt wool and damage the fabric. A well-cared-for jumper will last for years.
What do I do if I make a mistake several rows back?
If the mistake is small and does not affect the shaping, you can often leave it — your dog will not notice. If it affects the fit or looks very wrong, you can unravel back to the mistake, fix it, and knit forward again. This is easier than starting over. Keep your pattern notes and stitch markers handy so you know exactly where you are when you restart.