Dog sweater and coat size calculator
Enter your dog's chest girth and back length. You get the most likely sweater or coat size and the size on three makers' charts, with the working shown.
Tim de JongWidest part of the rib cage
Base of neck to base of tail
Optional, check it against the coat's collar
Most likely size
XS
XS on a chest-girth chart like Ruffwear's. Coat sizes aren't standard, so use these as a guide and check the chart of the coat you buy.
Three makers, three ways of naming sizes: letters, back length in cm, and S/M/L.
How we got there
- Chest 18 in: Ruffwear apparel XS (17–22 in).
- Back 15 in = 38 cm: Hurtta size 40, the next size up (Hurtta's advice between sizes).
- Harry Barker: Medium by chest and back.
Chest decides the letter (Canada Pooch, Chilly Dogs); Hurtta sizes by back length and says to take the larger size between two. Sizes from Ruffwear, Hurtta and Harry Barker, checked October 2026.
Size charts were checked on each maker's website in October 2026. Clothing sizes aren't standard, so check the chart of the sweater or coat you buy.
How do you measure a dog for a sweater or coat?
The AKC lists three measurements for dog clothing: the length of the back, the girth of the chest and the size of the neck. Take them with your dog standing straight and its head up. Chilly Dogs suggests two people for this, one to hold the dog and one to measure.
- Back length (C): from the base of the neck, just in front of the shoulder blades, to the base of the tail. Stop at the rump; don't measure over the tail.
- Chest girth (B): around the deepest, widest part of the rib cage, just behind the front legs.
- Neck girth (A): around the base of the neck, where a collar sits. Pull-over sweaters with a closed collar have to fit over the head and around this.
Keep the tape snug but not tight. The AKC's two-finger rule (two fingers between the tape and your dog) applies to the chest and neck here too.
Dog sweater size chart
There is no standard size for dog clothing. Here are three real charts, each sized a different way. First, Ruffwear, which uses one chest-girth chart for its harnesses, life jacket and apparel:
| Ruffwear size | Chest girth |
|---|---|
| XXXS | 9–13 in (23–33 cm) |
| XXS | 13–17 in (33–43 cm) |
| XS | 17–22 in (43–56 cm) |
| S | 22–27 in (56–69 cm) |
| M | 27–32 in (69–81 cm) |
| L | 32–36 in (81–91 cm) |
| XL | 36–42 in (91–107 cm) |
Hurtta names its coats by back length in centimeters. Its Mudventure coat comes in 9 sizes from 25 to 65:
| Hurtta size | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 |
|---|---|---|---|---|---|---|---|---|---|
| Back length (in) | 9.8 | 11.8 | 13.8 | 15.7 | 17.7 | 19.7 | 21.7 | 23.6 | 25.6 |
And Harry Barker gives both measurements for each letter:
| Harry Barker size | Back length | Chest girth |
|---|---|---|
| Small | 12–14 in | 14–17 in |
| Medium | 14–17 in | 17–20 in |
| Large | 17–20 in | 21–24 in |
Compare the Mediums: Harry Barker's fits a 17 to 20 inch chest, Ruffwear's a 27 to 32 inch chest. A letter on its own is close to meaningless, which is why the calculator works from your measurements.
Chest or back length: which matters more?
Makers don't agree. Canada Pooch says chest girth is even more important than back length, and Chilly Dogs calls back length "a general estimate" to consider last. Hurtta, which designs adjustable coats, calls back length the most crucial measurement for jackets.
In practice, start with the chest, since it decides whether your dog can move freely in the coat. Then check the length. If it falls between two sizes, Hurtta and Canada Pooch both point you to the larger one, and an adjustable back or waist strap takes up the slack.
Does my dog need a sweater?
Not every dog does. The AKC lists the dogs most likely to benefit from a sweater or winter coat:
- small and toy breeds, which struggle most in the cold
- lean, short-coated dogs such as Whippets and Greyhounds
- hairless breeds and dogs with clipped or shaved coats
- young puppies, older dogs and dogs with chronic health conditions
The AKC also notes that healthy large breeds with a thick coat generally don't need one and could overheat. To decide on a given day, the is it too cold for my dog? tool weighs temperature, wind and coat type.
How should a dog sweater fit?
The AKC's test is simple: a sweater that fits lets your dog walk, run and play normally, without being too big or too tight. After putting it on, watch your dog move for a minute and check that it can lift its legs freely and that the fabric doesn't bunch under the front legs.
Supervise your dog while it wears clothes; the AKC warns that an unsupervised dog can get tangled. Wash coats regularly, since they collect hair and dander. If you are kitting out for snow, the dog boot size calculator covers paws, and the harness size calculator uses the same chest measurement.
Frequently asked questions
What size is a medium dog sweater?
It depends entirely on the brand. Ruffwear's Medium fits a 27 to 32 inch chest, while Harry Barker's Medium fits a 17 to 20 inch chest. Always compare your dog's measurements with the chart of the sweater you are buying.
Should I size up in dog clothes?
When you are unsure, yes. Canada Pooch advises the size up so it fits the chest comfortably, and Hurtta suggests the larger size when a dog's back length falls between two sizes and the coat's length adjusts.
What if my dog's chest and back length are different sizes?
Go by the chest first. Canada Pooch and Chilly Dogs both call chest girth the most important measurement. A back length that is a little long can often be taken in on coats with an adjustable back, such as Hurtta's.
Where do you measure a dog's back length for a coat?
From the base of the neck, just in front of the shoulder blades, to the base of the tail, not over the tail. Have your dog stand straight with its head up; Chilly Dogs suggests two people, one to hold the dog and one to measure.
Can my dog wear a sweater all day or overnight?
The AKC advises against leaving a dog unattended in a sweater, because an unsupervised dog can get tangled in it. Take it off before you leave your dog alone at home or in a crate, and when your dog is back indoors in the warm.
Sources
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