How to Measure Your Dog for a Collar, Harness, Coat or Bed
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To measure your dog, use a soft tape measure and take three body measurements: around the neck where a collar sits, around the widest part of the chest just behind the front legs, and along the back from the base of the neck to the base of the tail. For a bed, measure your dog from nose to tail while lying down, then add extra space so they can stretch out comfortably.
Getting these numbers right takes five minutes and saves a lot of guesswork. Here is how to do each one properly, and how to use the results when you shop.
What you need
- A soft, flexible tape measure, the kind used for sewing. If you only have a rigid metal tape, use a piece of string or ribbon, mark it, then lay it against a ruler.
- A few treats to keep your dog relaxed and still.
- A second pair of hands, if your dog is wriggly.
- Somewhere to note the measurements, in centimetres.
Measure with your dog standing squarely on all four feet, on a flat surface. If your dog has a thick coat, keep the tape snug against the body rather than skimming the top of the fur.
Step 1: Neck (for collars)
- Find the spot where a collar naturally sits, around the middle of the neck, a little above the shoulders.
- Wrap the tape around the neck so it is snug but not tight.
- Note the measurement.
- Apply the two-finger rule: when the collar is on, you should be able to slide two fingers flat between the collar and your dog's neck. The collar should not slip over the head, but it should not press in either.
When choosing a size, look for a collar whose adjustable range comfortably covers your dog's measurement, ideally with your dog's neck sitting somewhere in the middle of that range rather than at the very end. This leaves room to adjust for coat changes or a growing puppy.
Not sure where your breed usually falls? Our dog collar size guide by breed gives typical ranges, but your own measurement always comes first.
Step 2: Chest or girth (for harnesses and coats)
- Find the widest part of your dog's ribcage, usually just behind the front legs.
- Wrap the tape all the way around at that point.
- Keep it snug, and note the number.
The chest measurement is the most important figure for a harness. A well-fitted harness should allow the same two-finger gap under the straps and should not rub behind the front legs. Harnesses such as our Pimlico Harness, which has adjustable chest and girth straps, give you room to fine-tune once it is on. For more on fit and style, read our harness guide.
Step 3: Back length (for coats and jumpers)
- Locate the base of the neck, where the collar sits at the top of the shoulders.
- Run the tape along the spine to the base of the tail, where the tail meets the body.
- Note the measurement.
Back length is usually the key measurement for coats, alongside the chest. A coat that is too short leaves the lower back exposed, while one that is too long can get in the way when your dog goes to the toilet. If your dog is between sizes, check the brand's size chart for chest as well as length, and consider which matters more for your dog's shape. Deep-chested breeds such as whippets, and long-backed breeds such as dachshunds, often need particular attention here.
Step 4: Bed size
Beds are less about the tape around your dog and more about how your dog likes to sleep.
- Watch how your dog sleeps. Curlers tuck their nose to their tail. Sprawlers stretch out on their side or back.
- Measure them in that position. For a curler, measure across the curled-up shape at its widest. For a sprawler, measure from the tip of the nose to the base of the tail while they are lying stretched out.
- Add space. Add roughly 15 to 30cm to that measurement so your dog can turn, shift and stretch without hanging over the edge. Allow more for sprawlers, and for beds with raised sides, where the usable sleeping area is smaller than the outer dimensions.
- Check the weight guidance as well as dimensions, since many beds give an approximate weight range for each size.
As an example, our Richmond Bed comes in Regular (45 to 50cm diameter, up to approximately 7kg), Large (55 to 60cm, approximately 6 to 12kg) and XL (65 to 70cm, approximately 12 to 20kg). For more on choosing a bed, see our guide on how to choose a luxury dog bed.
Quick reference table
| Measurement | Where to measure | Used for | Fit check |
|---|---|---|---|
| Neck | Middle of the neck, where a collar sits | Collars | Two fingers fit flat underneath |
| Chest or girth | Widest part of the ribcage, just behind the front legs | Harnesses, coats | Two fingers under straps; no rubbing behind legs |
| Back length | Base of neck to base of tail, along the spine | Coats, jumpers | Covers the back without reaching the tail |
| Sleeping length | Nose to tail, lying in their usual position | Beds | Add roughly 15 to 30cm of space |
Common measuring mistakes
- Measuring over a collar or harness. Take everything off first for an accurate reading.
- Pulling the tape too tight. Snug is right; a tape that dents the fur will give you a size that is too small.
- Measuring a sitting dog for length. Back length should be taken while your dog is standing.
- Using an old measurement. Puppies grow quickly, and adult dogs can change shape with age or weight. Re-measure before each new purchase.
- Ignoring the size chart. Sizes such as S, M and L vary between brands, so always compare your numbers with the chart for the specific product.
Frequently asked questions
How tight should a dog collar be?
Snug but comfortable. You should be able to slide two fingers flat between the collar and your dog's neck, and the collar should not be loose enough to slip over the head.
What if my dog is between two sizes?
Check the full size chart for the product. For adjustable collars and harnesses, choose the size where your dog's measurement sits nearer the middle of the range. For coats, consider whether chest or length is the tighter fit for your dog.
How much bigger should a dog bed be than my dog?
Measure your dog lying in their usual sleeping position, nose to tail, then add roughly 15 to 30cm. Sprawlers and beds with raised sides need the more generous end of that range.
How often should I re-measure my dog?
Re-measure puppies frequently while they are growing, and check the fit of their collar weekly. For adult dogs, re-measure before buying anything new, especially after any change in weight.