Knowing how to measure your dog for clothes means taking three core measurements: neck circumference, chest girth at the widest point, and back length from the base of the neck to the base of the tail. Most sizing problems come from guessing chest size or measuring back length incorrectly. Get those two right and most things fit well enough to be useful.
The first coat I bought arrived and didn’t make it past his shoulders. The second was so long it dragged on the ground. I’d measured something, but clearly not the right things. Once I worked out where the tape actually needed to sit, it became straightforward.
If you’re looking for coat recommendations, take a look at my article to 10 practical outdoor dog clothing essentials every owner should have, where I cover the best options for rain, winter, summer, hiking and everyday adventures.
What You Need Before You Start
A soft measuring tape is the only thing that works properly. The kind used for sewing. A ruler or a piece of string that you then measure against a ruler will give you something approximate, but not accurate enough if the fit matters.
You also need the dog to stand still for about two minutes. Not sit. Not lie down. Standing, weight evenly distributed, head in a normal position. If they won’t stay still, wait until they’re calm or slightly tired. Measuring a wriggly dog gives you useless numbers.
Neck Circumference
This is where a collar would sit. Wrap the tape around the base of the neck, where it meets the shoulders, and add two fingers’ width of space. That extra room stops the garment sitting too tight or rubbing.
If the dog has a very thick coat, press the tape down gently so you’re measuring the actual neck, not just the fur. Coats compress when fabric sits over them. If you measure the fluff, the neck opening will be too large.
Chest Girth
This is the measurement most people get wrong. The chest girth needs to be taken at the widest part of the ribcage, which is usually just behind the front legs. Not in front of them. Not halfway down the body. Right behind the legs where the chest is broadest.
Wrap the tape all the way around, keeping it level and snug but not tight. The dog should be able to breathe normally. Again, add a bit of room. I usually add about an inch for smaller dogs, two inches for larger ones. This gives enough space for the coat to sit comfortably without restricting movement or panting.
If the chest is too tight, the coat won’t go on. If it’s too loose, it will slip and twist and become irritating.
Back Length
Measure from the base of the neck, where the collar sits, to the base of the tail. Not the tip of the tail. The base, where it starts. Keep the tape along the spine and make sure the dog is standing with their back flat, not arched or stretched.
A lot of sizing charts use this measurement to determine the overall size. If you measure it with the dog sitting or with their head raised, you’ll get a longer number than you should, and the coat will be too big.
Weight and Breed Are Not Enough
Sizing charts often list weight ranges or breed suggestions. A medium Labrador and a medium Greyhound weigh about the same but have completely different body shapes. One is broad and muscular. The other is narrow and deep-chested. Weight alone tells you very little about how a coat will sit.
Always use the actual measurements. If the chart gives you a size based on weight that contradicts what your tape measure says, trust the tape measure.
When One Measurement Falls Between Two Sizes
This happens often. The chest measurement says large, but the back length says medium. In that case, go with the larger size for the chest. A coat that’s slightly too long is annoying. A coat that’s too tight across the chest is uncomfortable and restrictive.
You can adjust length by rolling a hem or cutting and hemming if the material allows it. You can’t make a tight chest bigger without ruining the garment.
Different Styles Fit Differently
A raincoat with an open belly is different to a fleece that wraps all the way around. A jumper with sleeves needs more precise sizing than a simple back-covering coat. If you’re buying something with leg holes, measure the distance between the front legs as well, particularly for barrel-chested or very narrow dogs.
Adjustable straps help, but they don’t fix a fundamentally wrong size. A coat that’s two sizes too small won’t work just because it has a buckle.
Signs the Fit Is Wrong
You’ll know quickly if something doesn’t fit properly. Here’s what to look for once the coat is on:
- Restricted movement: If the dog can’t sit, walk normally, or turn their head comfortably, the chest or neck is too tight.
- Twisting or sliding: If the coat keeps rotating or slipping to one side, the chest is too loose or the back length is wrong.
- Rubbing or chafing: Check under the front legs and around the neck after the first wear. Red skin or flattened fur means the fit is too snug in that area.
- Dragging fabric: If the back length is so long that it hangs past the tail or drags on the ground, it will get wet, dirty, and caught on things.
A properly fitted coat should sit flat along the back, stay in place when the dog moves, and allow them to behave exactly as they normally would. If they’re walking stiffly or trying to shake it off, something is wrong.
Remeasure for Growing Dogs or Weight Changes
Puppies grow quickly and unevenly. A measurement taken at four months will be useless by six months. If you’re buying for a young dog, expect to size up within a few weeks. Some people buy adjustable coats for this stage, though they rarely fit as well as a properly sized garment.
Older dogs can lose or gain weight as their activity levels and metabolism change. If you’re using the Dog Years to Human Years Calculator, you’ll get a sense of where your dog is in their life stage, which can help you anticipate when their shape might be shifting. A coat that fit well last winter might be too loose or too tight this year. Remeasure if it’s been more than six months or if their body shape has visibly changed.
What to Do If Nothing Fits Properly
Some dogs have proportions that don’t match standard sizing. Very deep-chested breeds, dogs with unusually long backs, or those with thick necks and narrow chests often fall outside the range that mass-produced coats are designed for.
In that case, adjustable designs with multiple straps work better than pull-on styles. Or you look for brands that cater to specific body types. Greyhound coats, for example, are cut differently to account for the deep chest and narrow waist. Dachshund coats are longer relative to chest size.
Custom-made is an option if nothing else works, though it costs more. You send the measurements and they make it to fit. I’ve not needed to go that far, but I know people who have for dogs with unusual builds, and it solved the problem.
Keep a Record of What Worked
Once you’ve found a coat that fits well, write down the brand, the size, and the measurements you used. Sizing is not consistent across manufacturers. A medium in one brand might be closer to a large in another. If you need to buy again, having that reference saves a lot of guessing.
Take the three measurements every time. Double-check the sizing chart for the specific brand. Go up a size if the chest is between two options. That’s the short version, and it works for most dogs most of the time.
This article is for informational purposes only. For advice specific to your dog always speak to your vet.