How to Measure Your Dog for a Jacket

Three measurements decide fit: back length from the base of the neck to the base of the tail, chest girth at the widest point just behind the front legs, and neck circumference. Take them with a soft tape on a standing trail partner, record them in inches, and check them against our size guide before you order. The articulated cut handles a range of builds, but the numbers come first.

We learned this the hard way, which is how most of it gets learned. A layer that looked right on the floor turned into a problem 2 miles up, flapping at the shoulders in a crosswind while the wind found every gap it left open. The fix was not a better fabric. It was a tape measure and 10 quiet minutes before the order ever went in.

Why fit decides whether a layer earns its place

A layer that does not fit is dead weight, and dead weight is the one thing we will not carry. Gear earns its place in the pack, or it doesn't go. Fit is where that gets decided. Too loose and a shell flaps in wind, lifts at the hem, and funnels cold air against the body instead of holding a still layer of warmth over it. Too tight and it pulls across the chest, restricts the reach of the front legs, and rides up the back on a steep climb until it is bunched at the shoulders doing nothing.

We cut articulated patterns, shaped to the way a moving body actually bends rather than to a flat rectangle. That cut tolerates a range of builds, but it still has to start from the right size. The shaping cannot rescue a number that was wrong by 2 inches. Get the size right and the articulation does its job; get it wrong and you spend the day fighting the garment instead of climbing.

Fit also carries across the whole line, not just one piece. The Shell, the Puffy, and the Fleece connect with our patent-pending toggle-and-loop system and stack on one another, so the same body has to read the same across all three. That is the point of the system: how our layering system stacks depends on getting the underlying measurements right before any of it goes on the dog.

It is tempting to skip the tape and size by breed. We understand the urge, and we still tell people not to do it. Two dogs of the same breed can land in different sizes, and the averages you find online are built from a thousand dogs that are not yours. The few minutes a real measurement takes are cheaper than the alternative, which on a made-to-order piece like the Traverse Shell means a return and a re-order instead of a quick swap. If you are still working out which pieces you need before you size them, start with choosing the right layer for the conditions.

Get the numbers right once and every layer in the system sits the way it should.

What you need before you start

The tool that matters is a soft fabric tape, the kind a tailor uses. It follows the curve of the body, which is exactly what you are trying to capture. If the only tape in the house is a rigid carpenter's tape, do not force it around the chest. Lay a length of string along the dog instead, mark where it meets, then measure the string flat against a ruler. The result is the same; the string just does the bending the rigid tape will not.

Stance is the other half of an accurate reading. Measure your trail partner standing square on a flat surface, weight even on all legs, head level and forward. A dog that is sitting, leaning, or twisting to look at you will give you a number that does not match the dog. This is where a second person earns their place, holding the lead and offering a reward so the dog stays put and faces forward for the 30 seconds it takes.

Take every reading against the dog's fur, snug but not compressing. You are measuring the body, not cinching the tape down on it. Snug enough that it does not sag, loose enough that you are not squeezing the chest smaller than it is. Compress the tape and you will order a layer that compresses the dog.

Write the numbers down the moment you take them, in inches, every one. Memory is not a measuring tool, and the difference between two close readings is exactly the difference that decides a size. Measure twice while you are at it. If the two readings disagree, take the larger one. A hair of room is recoverable on the trail; a layer that is genuinely too small is not.

Pick your moment, too. A dog fresh off a run is a poor subject: panting flares the ribcage, and a tape taken mid-breath reads a size too big. Give it a few minutes to settle. Ambient cold works the same trick in reverse. Measure indoors at room temperature, not out in a driveway wind where a hunched, tense body reads smaller than it actually moves. A calm trail partner on a warm floor gives you the number the layer has to fit across a whole season, not the outlier at either end of the day.

Accurate fit starts with a soft tape, a standing dog, and numbers you write down instead of trust to memory.

Back length: base of the neck to the base of the tail

Start at the base of the neck. That is the spot at the top of the shoulders where a collar naturally falls, the high point of the back just behind the neck itself. Find the base of the tail at the other end, where the tail meets the spine, not where it begins to taper. Those two points are the start and finish of the measurement, and naming them precisely matters more than people expect.

With the dog standing square, run the tape flat along the topline, following the spine from the one point to the other. Keep it on the midline of the back; let it ride down a flank and the number inflates. This reading sets coverage, which is the whole reason an outerwear layer exists in cold and wind, and on a Traverse layer it also sets the size. The chest and neck closures adjust across a wide range; the back does not, so this is the number we size to. The AKC's guidance on keeping dogs safe in cold weather is blunt about it: a layer earns its keep by covering the torso and fitting properly, and a number that is off at either end undercuts both.

Coverage cuts two ways. Too long and the layer fouls the tail and hindquarters, catches when the dog squats, and gets in the way of the gait. Too short and it leaves the lower back and loin exposed, which is the stretch of spine you most want covered when the wind comes up on a ridge. Measure to the base of the tail, never the tip. We are covering the back, not the tail; the tail does its own work and does not want a sleeve.

Back length, measured spine-straight from neck base to tail base, is the single measurement most likely to decide the size.

Chest girth: the widest point behind the front legs

If back length sets the size, chest girth confirms it. This is the number that tells you the size the back picked will close around the body. Wrap the soft tape all the way around the torso at its widest point, just behind the front legs and the armpits, and bring it back to where you started. That band around the deepest part of the ribcage is the chest girth measurement. Length tells you the size; girth tells you whether that size closes around the body with adjustment to spare.

Tension is everything here. Keep the tape snug against the body, then check that you can still slide a finger or two underneath it. That margin is not slack for its own sake; it is the room the dog needs to breathe deep on a climb and reach with the front legs at speed, without leaving so much gap that wind pours in. Take the reading with the dog standing and breathing normally, not mid-pant and not held so still the ribcage flattens. Too tight a number and the layer restricts the chest exactly when the dog is working hardest. Too loose and you have built the wind a door.

Build changes the math. A deep-chested dog often runs larger in girth relative to length than the proportions you would guess from a photo, which is precisely why we measure instead of assume. When the girth number and the back-length number point to two different sizes, start from the back length and check the girth against that size's range. Inside the range, the closures take up the difference. Above it, size up, because a piece that will not close around the ribs cannot do its job no matter how well the length lines up.

One habit worth building here: take the girth twice, once tight behind the front legs and once a finger-width further back, and keep the larger of the two. The widest band of the ribcage is the one the layer has to clear, and on a well-muscled or deep-chested build it can sit a touch further back along the torso than your eye expects. The extra ten seconds is the cheapest insurance on the whole measurement, and it is the reading that most often separates a size that closes clean from one that restricts movement.

Chest girth at the widest point behind the front legs is the check that confirms the size back length gave you.

Neck, and the in-between build

Measure the neck low, down where it meets the shoulders and a collar sits, not high up on the throat. The low reading is the one that matters because that is where the collar opening of a layer has to seal. Measured too high, the number comes in small and the opening ends up loose at the base, which is the gap that lets a draft run straight down the chest.

That seal is not cosmetic. Wind strips heat off a body faster than still air at the same temperature, which is the whole logic of the National Weather Service wind chill chart: the harder it blows, the colder the air effectively gets against skin and coat. A neck opening that closes cleanly keeps that moving air on the outside of the layer where it belongs. A loose one hands the wind a head start.

Now lay your three numbers next to each other. Many dogs land between two sizes on at least one of them, and a fair number land between sizes on all three. Note exactly where each one falls rather than rounding in your head. The articulated cut is built to tolerate that kind of range, but consistent in-between numbers are a signal to read the fine print, not to guess. That is the moment to open our size guide and check the build notes against what your tape is telling you.

Deep-chested and barrel-chested dogs are the usual in-between cases, and they have their own guidance for good reason. A barrel chest can throw the girth past the top of the range the length predicts, which is the one case where the chest, not the back, moves you up a size. If that is your dog, we wrote up sizing a deep-chested trail partner for exactly that question, because the standard rule of thumb bends for that build.

Neck circumference rounds out the picture, and where your three numbers disagree is exactly where the size guide earns its keep.

Turning your numbers into a size

Do not average the three numbers. Averaging hides the one measurement that should drive the decision and invents a body that does not exist. Instead, lay all three side by side and read them against the chart in our size guide as a set. Most of the time they agree and the size is obvious. When they do not, you have a real decision to make, and it has an order of operations.

Start with the back length. The chest and neck closures on every Traverse layer adjust across a wide range, so a span of girths fits each size; the back does not adjust, so it is the number that picks the size. Once the back length points you to a size, check the chest girth against that size's range. Inside it, you are done. Above it, size up, because a layer that will not close around the ribs is not a layer, regardless of how the length reads.

A worked example makes the order of operations plain. Say the back length sits squarely in one size and the girth lands near the top of that size's range. Stay with the size the back picked; the closures are built for exactly that spread. Now say the girth lands above the range. Go up. The larger layer's length runs a little long, but a half-inch of extra coverage over the loin costs nothing on the trail, while a chest that will not close costs the dog heat every time the wind comes up on an exposed stretch. And if the back length itself sits on the line between two sizes, go up there too: we do not drop a size to chase a shorter back if it means squeezing the ribs the dog breathes with on a climb.

This matters more here than it would with off-the-shelf stock. Every Traverse layer is made to order, sewn in Colorado in small batches rather than pulled from a wall of inventory. There is no bin of every size to swap through on a whim, which is the trade for a piece sewn only after the order comes in. The set sizes carry multiple adjustment points, and the articulated cut fits a range of builds, but the right size up front is still the difference between a layer that ships ready and a re-order that costs you a season. Equipped, not just dressed.

The reward for getting it right is that you only do it once. The same three numbers size the Shell, the Puffy, and the Fleece, because the system is cut to stack and connect rather than as three unrelated garments. Measure once and the numbers carry across all of it. The one caveat is time: a young dog still filling out, or an older one that has just put on trail conditioning after a winter off, will change shape. Re-measure seasonally for a growing or recently conditioned trail partner, and let the tape, not last year's number, make the call.

Three honest measurements plus the size guide turn an order into a layer that fits the first time.