How To Measure A Dog For A Harness

When choosing a harness for your dog, you need to find one which is the perfect fit. Not only will this be more comfortable for your dog, but it will also allow better control for you.

To find the perfect size harness for your dog, you need two measurements – their girth (chest measurement) and length. You then need to match these measurements up to the guidelines given by your chosen manufacturer/product. They may also ask you to measure the neck circumference.

Many harness companies will also use your dog’s weight as a guideline as to whether the harness is suitable. Two breeds can be the same size but be very different weights. A harness may not be strong enough to cope with a very strong Bully breed, for instance.

Measuring a dog for a harness

To measure your dog for a harness, you will ideally have a soft tape measure. If not, anything which is flexible to mould around your dog’s body shape is suitable.

A piece of string works well – you just work out the length of the string afterwards, using a ruler or traditional tape measure.

How to measure a dog for a harness


The girth is the chest measurement at the broadest section of their chest. This is often around the ribcage as opposed to closer to the stomach or armpits.

To measure for girth, get your dog on its feet and then wrap the tape measure around the largest section of its chest.


Measure your dog’s length from neck to tail. This will tell you how large your dog’s harness has to be. It is no good getting a very short harness for a long breed, nor a long harness for a short breed.

Harness styles can focus on the chest or main body of the dog. Which is best for you will depend on how much security your dog needs, and whether they pull.

For a dog who is a right little Houdini, a longer vest style may be more appropriate. For a dog who is very strong and chest-focused, a shorter harness that gives them plenty of padding and support around their shoulders could be best.


Depending on the brand of harness, you may also need to measure their neck. This is common in chest harnesses, such as the Julius K9. The neck ‘hole’ will be a certain size, so it is just to make sure that they will have enough space and it will sit correctly on the body.

When measuring your dog, take the exact measurement. Then, when finding a harness, add a little bit of extra space to that measurement. For example, if your dog is 102cm around its girth, add a few centimetres to get the right fit when finding its ideal measurement.


You should always know your dog’s weight, so you can check for any issues in health (such as over- or under-feeding). But check again just before buying a harness.

Some brands, particularly those which make harnesses for dogs that pull, will also have a weight guide. This tells you how much weight the harness strap or chest section will hold when under pressure. If your chosen harness won’t hold your dog’s weight, reconsider and choose another model, even if the measurements work out perfectly.

Dog harness measurement tips

  • Harnesses should be snug but not tight
  • They need to be adjustable to accommodate growing/changes in weight
  • One size in one brand doesn’t mean the same size in another brand
  • Don’t follow rough guides based on breeds – all dogs are different
  • Your dog may be just between two sizes – always go up and make it tighter

When properly sized, you should be able to fit two fingers in between the harness and your dog. It should also not cause your dog’s skin to bunch up, or their skin to chafe. Be careful with their chest and underarms when it comes to chafing.

If you notice any of these issues, try and measure your dog again. They may have their thicker winter coat or have put weight on. Most harnesses are adjustable to accommodate these changes.

If your harness is not adjustable, buy another one in a different style. Some breeds can simply find certain styles restrictive. Bully breeds with excess skin can find vest harnesses restrictive, for example.