There's nothing quite as adorable as a dog in a perfectly fitted puffer jacket — and nothing quite as miserable as a dog squirming around in one that doesn't fit. A jacket that's too tight pinches under the legs and limits movement. Too loose, and it twists, drags, or slips right off mid-walk.
The good news? You only need a few minutes, a soft tape measure, and a cooperative pup (or a treat-bribed one) to get the right size on the first try. This is the same approach we use at Gussied Up Pet Boutique when we help customers pick out cold-weather gear, and it works for puffer jackets, raincoats, sweaters, and harness vests alike.
If you've already read our collar measuring guide, this will feel familiar — just three measurements instead of one.
What You'll Need
- A soft fabric tape measure (the kind tailors use). If you don't have one, a piece of string and a ruler works in a pinch.
- A treat or two to keep your dog standing still.
- A second person if your dog is wiggly. Not required, but it speeds things up.
- Your dog standing squarely on all four legs on a flat surface. Sitting throws off the back length and chest measurements significantly.
The Three Measurements That Matter
For nearly every dog jacket, coat, or sweater on the market, you need three numbers: back length, chest girth, and neck circumference. Of the three, chest girth is the most important — it's the measurement that decides whether the jacket actually closes around your dog without pinching.
1. Back Length (the number most size charts ask for)
Back length tells you how long the jacket will be along your dog's spine.
- Start at the base of the neck, right where the collar naturally sits.
- Run the tape straight along the spine.
- Stop at the base of the tail — right where the tail meets the body, not partway down the tail.
Write this number down in inches.
2. Chest Girth (the most important number)
Chest girth is the circumference around the widest, deepest part of your dog's ribcage — usually just behind the front legs.
- Wrap the tape around the chest at its widest point, just behind the front legs and over the shoulder blades.
- Keep the tape snug but not tight — you should be able to slip two fingers underneath comfortably.
- Make sure the tape is level all the way around, not sloping up or down.
This is the number to trust when sizing. If your dog falls between sizes, always size up based on chest girth, even if back length suggests a smaller size.
3. Neck Circumference
Neck circumference is the loosest of the three and decides whether the jacket's opening goes over your dog's head comfortably.
- Measure around the base of the neck, where a well-fitted collar would sit.
- Snug, but with two fingers of room.
How to Read a Dog Jacket Size Chart
Every brand sizes a little differently — that's the unfortunate truth of dog apparel. A "medium" in one brand can fit like a "large" in another. Here's how to actually use a size chart:
- Find your dog's three measurements on the chart.
- If all three land in the same size, you're done. Order that size.
- If chest girth and back length disagree, follow chest girth. A jacket that's slightly long in the back is awkward; a jacket that won't close around the chest is unwearable.
- If you're between two sizes, size up. It's nearly always easier to live with a jacket that's slightly roomy than one that's slightly tight, especially over a winter coat or harness.
Don't trust weight ranges alone. A 30-pound stocky Frenchie and a 30-pound lean Whippet wear completely different sizes. Tape measure beats scale every time.
Common Mistakes to Avoid
We see the same handful of measuring mistakes over and over. A few minutes here saves a return later.
- Measuring while your dog is sitting. This shortens the back length and distorts the chest girth. Stand them up.
- Measuring over a thick collar or harness. Take both off first.
- Measuring too tightly. If the tape is digging in, your number will come out too small and the jacket will pinch.
- Forgetting fluffy coats. For double-coated breeds (Huskies, Golden Retrievers, Doodles, Pomeranians), press the tape gently down to the body through the fur. Measure the dog, not the floof.
- Measuring once. Take each measurement twice. If you get different numbers, take a third and average them.
Body Type Considerations
Some breeds need extra thought because their proportions don't match what size charts assume.
- Deep-chested breeds (Greyhound, Whippet, Doberman, Boxer, Vizsla): Their chest girth will run large relative to their back length. Size up based on chest.
- Broad-chested breeds (Bulldog, French Bulldog, Pug, Pit Bull-type breeds, Boston Terrier): Same story — chest girth will drive the size. Look for jackets cut for broad chests when available.
- Long-bodied breeds (Dachshund, Corgi, Basset Hound): Their back length will run long relative to chest girth. A few brands make breed-specific cuts that are worth the search.
- Tiny breeds (Chihuahua, Yorkie, Maltese): The neck opening is often the limiting factor. Measure carefully and choose adjustable closures if possible.
- Growing puppies: Don't oversize too aggressively. A jacket that's two sizes too big is more of a hazard than a help. Buy for now, replace as they grow.
Quick Reference Checklist
Before you click "order," confirm:
- ☐ Dog is standing squarely on all four legs.
- ☐ Tape measure is snug but allows two fingers underneath.
- ☐ Back length: base of neck to base of tail.
- ☐ Chest girth: widest part of ribcage, just behind front legs.
- ☐ Neck circumference: where a collar naturally sits.
- ☐ Sized up if between sizes.
- ☐ Double-checked the brand's specific size chart (not a generic one).
Frequently Asked Questions
Do I measure my dog with their collar on?
No — take it off. Same with any harness.
Should I measure for room to grow if my dog is still a puppy?
A little bit, yes — but no more than half a size up. Anything more becomes a tripping hazard.
Can I use a string instead of a tape measure?
Yes. Wrap the string around your dog where you'd measure, mark the spot with your fingers, then lay it flat against a ruler.
My dog has a thick winter coat — does that change the sizing?
It can. Measure down to the body rather than over the fluff, then size up half a size if the jacket will go over an already-fluffy coat.
What if I'm still not sure between two sizes?
Always size up, especially for puffer jackets and raincoats where you may want room for a sweater underneath. And of course, you can reach out to us directly — we'd rather help you get it right than have you return it.
Get Your Pup Gussied Up for the Season
Now that you know how to measure, you can shop with confidence. Browse our apparel collection for puffer jackets, sweaters, raincoats, and accessories curated for dogs of every size — and made to keep your four-legged family member warm, dry, and ridiculously cute.
See you (and your dog) at the Alpharetta Farmers Market on Saturday. 🐾
Have a sizing question we didn't cover? Send us a note or tag us on Instagram @gussieduppetboutique — we love a fit challenge.
