Dog Sweater Instructions for Any Size Dog

My dog sweater instructions for this one-piece  project.

Knitting this sweater requires basic techniques such as casting on and off, knit and purl stitches, as well as increasing and decreasing. 

Easy knit aqua dog sweater

Note that my instructions are not for any specific type of yarn or knitting needle size.

Instead, I show you how to create your own customized dog sweater pattern that you can make for your particular dog(s).

What’s Involved?

You’ll need to take accurate measurements of your dog and do some simple math. (Note: It doesn’t matter whether you use American or metric units.)

For best results, read through all the dog sweater instructions first. Take your time to understand each part.

Be prepared to give it more than one try, unraveling work if you need to. Give yourself permission to make mistakes…

Measurements for Dog Sweater Instructions

Write these down in pencil, then double check them.

Collar: Measure all the way around the neck where the collar goes.

Neck Length: From the collar area to the chest circumference.

Chest Circumference: All the way around the neck at the chest area, just in front of the legs.

Leg Diameter: Measure straight across the top part of your dog’s legs where they attach to the body.

Width Between Legs: Distance over the top of the dog between the leg diameter points.

Torso Circumference:Your dog’s body just behind the legs.

Torso Length: The distance from behind the dog’s legs to the end of the dog’s rib cage.

Flank Length: The distance from the dog’s rib cage to the dog’s privates.

Rear: The width across the dog’s back in front of the tail – you decide how far down you want the sweater to go on each side. 

Determine Your Knitting Gauge

Knit a test swatch

Make sure you use the same yarn and knitting needles that you plan to use for the project.

Cast on 20 stitches and knit at least 10 rows, each row of knit and purl combined counting as one row (also known as stockinette stitch).

Without stretching the swatch, record the number of stitches you knit and the number of rows (remember that is actually two rows – one of knit and one of purl) you created per inch (or per cm).

Aqua Dog Sweater Instructions: 
Collar & Neck

Step 1: Cast on and start rib stitch

A. Pebble’s collar measurement was 12.5 inches. My knitting gauge for stockinette stitch came to 5 stitches per inch.

  • This meant I would need to cast on 12.5 x 5 or 62.5 stitches. I chose to round this down to 62 stitches since I knew the knitted piece would stretch a little.

B. Knit an inch (2.5 cm) of rib stitch (K1, P1 or K2, P2) with the stitches you cast on.


Step 2: Determine neck length rows and increase in stitches 

A. Figure out how many rows you will need between the collar and chest circumference:

  • Take one inch (2.5 cm) off the measurement you had for your neck length (to account for the one inch of rib stitch you knitted). In Pebble’s case, this distance was 5.0 inches, so I took off one inch and came up with 4.0 inches. 
  • My gauge for the number of rows I knit per inch was 8. So I multiplied 8 by 4.0 and came up with 32 rows.

B. Figure out the difference between the number of stitches you started with and the number of stitches you need for the chest circumference. 

  • For example, Pebble’s chest circumference was 18.0 inches, or 90 stitches, using my gauge. So I needed to increase the piece by 28 stitches (90 – 62 = 28).

C. Using the above calculations, I learned I needed to increase the width of my knitting by 28 stitches over 32 rows.

  • Since 28 was pretty close to 32, I decided to knit 1/2 inch more of rib stitch without increasing and then switch to stockinette stitch, so that it would simplify the arithmetic as I could then increase 28 stitches over 28 rows.

D. Following your calculations, knit the ribbing until you are ready to start increasing. 


Step 3: Increasing for the neck using stockinette stitch

A. About increasing for these dog sweater instructions:

  • Only increase stitches on a knit (K) row
  • Increase by one stitch at each end for symmetry. This means you will add two stitches to the row each time. 
  • For Pebble’s neck, I figured out I needed to add stitches only every other knit row (28 divided by 2 = 14)
  • If you have trouble keeping track, use a safety pin, or a piece of wire twisty at the end of each row where you increased – you can also use a tally mark system.

B. Knit and purl the number of rows per your measurements, increasing as needed.

Aqua Dog Sweater Instructions: 
Leg Holes


These are fun once you get the hang of them! You are going to knit a section, cast off a certain number of stitches that will create the first leg hole, knit the number of inches required to the next leg hole, cast off that same number of stitches, and then knit to the end.

A. Next row, knit 10, cast off 14, knit to near end of row, cast off 13 stitches, knit 9 Purl to cast off stitches, turn work around and loosely cast on 14 stitches, turn work around again, and purl to next cast off lot. Turn work around, loosely cast on 13 stitches, turn work around again and purl to end of row. Knit across row, 88 stitches Purl across row, 88 stitches Repeat rows of knit and purl for the next inch and a half (24 rows).

Then decrease every knit row, two stitches on each end for 12 knit rows End with rib stitch, 2 K, 2 P for 12 rows.

Aqua Dog Sweater Instructions: 
Torso (Body)


This is where the two halves of the sweater come together under the belly and overlap for the Velcro. I used the Belly 2 measurement to determine the number of stitches to add to each end. Pebble’s body circumference came to 16.0 inches. I added an extra 1.5 inches for the overlap to get a total of 17.5 inches. The difference between that and the Flank 2 measurement of 13.0 inches was 4.5 inches. Since my gauge was 5 stitches per inch, I needed to add 22 stitches, or 11 on each side.

  • Pebble was measured as being 18 inches around at that point, including the 1 inch overlap.

Aqua Dog Sweater Instructions: 
Flank & Rear


  • I started with the Tail End number of stitches, but needed to increase to my Flank 1 number of stitches, which was 13.0 inches.
  • My Flank 2 measurement said I needed to increase the width by 4.5 inches (13.0 – 8.5) over 3.0 inches in height.
  • 3.0 inches x 7.0 rows per inch = 21 rows, and 4.5 inches x 5 stitches per inch = 22.5 stitches to be added.
  • Therefore, if I added one stitch on each end every Knit row, I would have 22 stitches added by the time I got to 21 rows – close enough to my measurements to work.
  • Once I had completed 21 rows, I added one more row of Purl so that I could start adding stitches to the next Knit row for the Body.


I used the rib stitch pattern (K1, P1) for the last inch. As with the neck, you can also do a pattern of K2, P2 for a wider rib.

That’s it for the instructions for this dog sweater. Hope you enjoyed the process of creating a custom sweater for your dog!