How to measure your dog for a coat — back length, chest girth and neck size explained with a simple step-by-step guide for UK dog owners.
Bad fit ruins good products. Half the time a coat gets blamed when the real issue is that someone guessed the size from a fuzzy product photo and a prayer.
Measure back length, chest, and neck properly, then check each brand's chart instead of assuming a medium is always a medium. It absolutely is not.
Three measurements decide nearly every coat: back length from the base of the neck to the base of the tail, chest girth at the widest point behind the front legs, and neck circumference at the base. Get those right and you have a fighting chance of buying the correct size first time.
Stand your dog on a flat surface. Do not attempt this while they are sitting down, spinning in circles, or trying to eat the tape measure.
Back length: Run a soft tape measure from the base of the neck — where the collar sits — to the base of the tail. This is the single most important number for coat sizing. Not the nose-to-tail length you see referenced everywhere else; you need the back length specifically.
Chest girth: Measure around the widest part of the chest, just behind the front legs. Keep the tape snug but not tight — you should be able to slip two fingers underneath easily. If your dog has a big barrel chest, take this measurement twice on different days. Dogs puff up slightly when they are tense.
Neck circumference: Measure around the base of the neck where the collar usually sits. This matters more than people think, especially for high-neck coats like the Hurtta range.
Weight: Worth noting even though it is not a primary measurement. If your dog is on the border between sizes, weight often helps you pick the roomier option over the one that will split at the seams by March.
Write the numbers down. Measure twice if you are unsure. Do not estimate.
Dog coats are sized for average body shapes, and most dogs are not average. Here is where breed type changes the calculation:
Barrel-chested breeds (Staffies, Bulldogs, Boxers): These dogs have a disproportionately wide chest relative to their back length. A coat sized correctly for their chest will often be a size larger than the back length suggests. Always size up for chest and check whether the coat has enough chest adjustment.
Deep-chested, lean builds (Greyhounds, Whippets, Lurchers): The opposite problem. The chest is deep front-to-back but not wide. Many standard coats gape at the sides or fail to stay put. Look for coats with proper belly straps or tailored fits.
Long-bodied breeds (Dachshunds, Basset Hounds): Standard back-length sizing runs short on these dogs. A coat that fits the neck and chest may be a length or two sizes up. Some brands like Hurtta offer extended back-length options specifically.
Small slim dogs (Chihuahuas, Italian Greyhounds, Miniature Pinschers): Standard small-dog sizing often still runs wide. These dogs genuinely need coats designed for their body type, not just scaled-down versions of adult coats.
Different brands size differently. Do not assume a Medium in one range is a Medium in another.
Hurtta: sizes by back length primarily. Their system is the most precise but also the least forgiving of guesswork — use their full sizing chart, including the neck and chest columns.
Ancol: more relaxed sizing that suits a wider range of body shapes. A good option if your dog is roughly average-shaped.
Barbour: sizes run noticeably small and the cut is slim. If your dog has a broad chest or a short wide body, size up or look elsewhere.
This happens more often than it should. When two measurements put you in different sizes, use this logic:
Take measurements without the collar if possible, or at least loosen it. Collar bulk can add a false centimetre to neck measurements.
Yes. If you are measuring a dog that will be wearing the coat over a thick winter undercoat, add 1–2 cm to the chest measurement. Dogs like Labs and Spaniels in full winter coat are noticeably broader through the chest than in summer.
If you are measuring your dog for a coat, these are the two we recommend starting with — one waterproof, one winter-insulated — both with clear size charts that match the measurements above.
Approx. price: ~£65
The strongest all-round choice for owners who need reliable, repeated rain protection. Full-body suit design covers the belly and neck, the fabric is flexible and quiet in motion, and the cut works across a wide range of dog shapes.
Approx. price: ~£50
Quilted insulation and a tartan lining make this a genuinely warm coat for cold British walks. The slip-over-head design with a belly Velcro strap is one of the easiest to get on a reluctant dog, which matters when you are standing in the cold at 7am.
Take measurements without the collar if possible, or at least loosen it. Collar bulk can add a false centimetre to neck measurements.
Yes. If you are measuring a dog that will be wearing the coat over a thick winter undercoat, add 1–2 cm to the chest measurement. Dogs like Labs and Spaniels in full winter coat are noticeably broader through the chest than in summer.
Buy the Large and adjust the belly strap. A coat that will not fasten across the chest is useless. A coat that is slightly loose in length but fits the chest and adjusts snugly at the belly is perfectly functional.
Stand the dog squarely on a flat surface. Measure back length (base of neck to base of tail), chest girth (widest part behind the front legs) and neck circumference (at the base of the neck). Always compare to the specific brand's size chart — sizes are not standardised.
Measure the back length from the base of the neck to the base of the tail, chest girth at the widest point behind the front legs, and neck circumference at the base. Compare all three to the specific brand's size chart — coat sizing is not standardised across brands.
At 20kg most dogs are considered medium. Breed frame matters: a 20kg Cocker is squarely medium, a 20kg Border Collie is medium-large, and a 20kg Staffy is built like a small large. For harness and coat sizing always measure rather than relying on weight alone.
Barbour sizes by back length from the base of the neck to the base of the tail. Measure with the dog standing square, round up if between sizes, and check Barbour's own chest girth guidance — their coats run slightly snug at the chest on deep-chested breeds.
The 90-10 rule applies to treats and training rewards: 90% of the dog's calorie intake should come from its main food, with no more than 10% from treats. Going over the 10% can unbalance the diet and cause weight gain.
A few obvious extras that buyers on this page almost always need. We do not keep specific picks for these — the Amazon search results for each are consistently good.
You cannot measure a dog for a coat with a rigid ruler. A soft sewing tape measure is £3 on Amazon and does the job properly.
Typically £
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