To measure a dog for a raincoat, you need two numbers: chest girth (around the widest part of the ribcage, just behind the front legs) and back length (from the base of the neck to the base of the tail). Compare both to the size chart on the listing, and if your dog lands between two sizes, size up so the coat covers the back and doesn't pull at the chest. Breed and weight alone won't get you a good fit.
Knowing how to measure a dog for a raincoat sounds obvious, but the first coat most people buy is ordered by "medium" and returned, because two dogs at the same weight can have very different builds. This guide walks through exactly what to measure, how to read a size chart, and what a good fit looks like once the coat is on.
How to measure a dog for a raincoat: the three numbers
Three measurements cover almost every raincoat sold today. Use a soft tailor's tape, not a metal one, and measure while your dog is standing normally. If your dog won't hold still, a piece of string and a ruler works just as well.
- Chest girth: Wrap the tape around the deepest part of the chest, right behind the front legs. Keep it snug against the fur but not compressing it. This is the measurement that decides whether the coat closes at all.
- Back length: Measure along the spine from where the collar sits (base of the neck) to the base of the tail. This decides how much of your dog's back stays dry.
- Neck circumference: Wrap the tape where a collar would sit. Most raincoats are forgiving here, but hooded styles and coats with a fixed neck opening need it.
Write all three down before you shop. It takes two minutes and saves an exchange.
How do you read a dog raincoat size chart?
Every brand sizes differently, so ignore the letter and look at the ranges. As an example, our lightweight waterproof pet raincoat runs XS through XL, with chest girth from 11 inches at XS up to 22 inches at XL, and back length from about 7 to 16.5 inches. A dog with a 16-inch chest and 12-inch back fits squarely in the M range on that chart, even if that same dog wears an L in a different brand's sweater.
A few rules that hold across most charts:
- Chest girth wins ties. If chest says M and back length says S, go with M. A coat that's slightly long is fine; a coat that won't close at the chest is useless.
- Between sizes means size up. Rain gear should cover, not cling. A drawstring or belt lets you cinch a slightly larger coat; nothing fixes one that's too small.
- Check for skipped sizes. Some styles jump from XS straight to M. Our buckle pet trench coat does this, so a dog that normally wears S may need to go up to M.
How should a dog raincoat fit once it's on?
Put the coat on and watch your dog walk, sit, and lie down before you take the tags off. You're looking for:
- Two fingers at the chest strap or belly band. Same rule as a collar: snug with light resistance, not tight.
- Full leg movement. The front of the coat shouldn't cut into the armpits when your dog reaches forward. Rubbing there shows up as bare patches within a couple of weeks.
- Coverage to the tail base, not past it. A coat that hangs over the tail gets soaked from underneath and can interfere with bathroom breaks.
- Hood (if there is one) stays back. A hood that flops over the eyes is worse than no hood. Many dogs tolerate hoods only when they're loose.
If your dog freezes, walks stiffly, or immediately tries to shake the coat off, that's normal for the first couple of wears. Try a few short sessions indoors before the first rainy walk. If the stiffness doesn't fade after a week, the fit may be wrong, or your dog may simply be one of the ones who doesn't like coats. That part depends on the dog.
Does material matter as much as fit?
For rain, yes. Look for a coated or laminated polyester shell rather than a "water-resistant" fleece. Water-resistant means a light drizzle beads off for a few minutes; waterproof means your dog comes home dry after a twenty-minute walk. Other details worth checking:
- Closure type. Drawstrings and buckles adjust to your dog's shape; hook-and-loop strips are quick but lose grip as fur gets in them.
- Lining. An unlined shell is fine for warm rain. For cold rain, a light lining or a sweater layered underneath (measure with the sweater on) keeps a short-coated dog comfortable.
- Leash opening. If your dog wears a harness, check for an opening along the spine so the coat can go over the harness.
Can you use the same measurements for other dog clothes?
Mostly. Chest girth and back length are the two numbers used for sweaters, hoodies, jackets, and jumpsuits across our pet clothing collection. The difference is ease: a stretchy knit sweater can run closer to your dog's actual chest measurement, while a non-stretch raincoat or trench needs a little room. When in doubt, check the listing's stretch note and size chart rather than reusing a size from a different garment.
If you have a dog and a cat at home, the process is the same for both. We covered the cat side in how to measure a cat for a sweater or harness, and the chest-first rule holds there too.
FAQ
How do I know what size raincoat my dog needs?
Measure chest girth and back length with a soft tape, then match those numbers to the size chart on the specific coat you're buying. Don't go by breed or weight, and size up if your dog falls between two sizes.
Should a dog raincoat be tight or loose?
Slightly loose. You should be able to slide two fingers under the chest strap or belly band, and your dog should be able to reach forward with the front legs without the coat pulling at the armpits. A drawstring or belt then takes up any extra room.
Do dogs actually need raincoats?
It depends on the dog. Thick double-coated breeds shed water on their own and usually don't need one. Short-haired, small, thin, or senior dogs get cold fast when wet, and a raincoat keeps the walk from turning into a shivering, towel-heavy ordeal. Many people also use one simply to keep mud off the couch.
Quick recap
That's really all there is to how to measure a dog for a raincoat: take chest girth and back length, let chest girth decide the size, size up when in between, and check for two-finger room and free leg movement before the first wet walk. Browse our dog raincoats and cold-weather layers, each listed with real measurements in inches. Orders over $75 ship free.
