How to Measure Your Dog for a Harness, Collar and Clothing

To measure your dog correctly, you will usually need three measurements: their neck, chest and back length. Use a soft tape measure, keep your dog standing naturally and compare the results with the size guide for the individual product.

It sounds simple, but a few small details can make all the difference. A considered fit helps a harness sit securely, allows clothing to move comfortably and ensures your dog can enjoy every walk without unnecessary rubbing or restriction.

Here is our step-by-step guide to measuring your dog with confidence.

What you will need

Before you begin, gather:

• A soft fabric tape measure

• A few of your dog’s favourite treats

• A pen and paper or your phone

• An extra pair of hands, if your dog is particularly wriggly

If you do not have a flexible tape measure, use a piece of non-stretch string or ribbon. Mark where the ends meet, then lay it flat against a ruler.

Measure in centimetres and take each measurement twice. If the two results are different, allow your dog to settle and try again.

Before you measure your dog

Ask your dog to stand naturally on a level surface, with all four paws on the ground. Measuring while they are sitting, lying down or stretching can alter their proportions and make the result less accurate.

Keep the tape flat against their coat without pulling it tightly. You are looking for their true body measurement, so do not add extra centimetres unless the product’s size guide specifically tells you to.

For dogs with particularly thick or fluffy coats, gently smooth the fur without compressing it.

The three key dog measurements

Measurement	Where to measure	Commonly used for
Neck	Around the base of the neck, where the collar naturally sits	Collars, harnesses and clothing
Chest girth	Around the widest part of the ribcage, usually just behind the front legs	Harnesses, coats, shirts and jumpers
Back length	Along the spine, from the base of the neck to the base of the tail	Coats, raincoats, shirts and other clothing

Always check the instructions for the product you are considering. Different designs may sit in slightly different places, even when they appear similar.

1. How to measure your dog’s neck

Wrap the tape around the base of your dog’s neck, where their collar would naturally sit.

The tape should be level and close to the coat, but not pulled tight. Make a note of the full circumference in centimetres.

For a harness, the neckline may sit slightly lower than an everyday collar. Follow the diagram or instructions on the relevant product page to make sure you are measuring in the correct place.

Checking the fit of a dog collar

Once the collar is fastened, you should be able to slide two fingers comfortably between the collar and your dog’s neck. It should feel secure without pressing into the skin, and it should not be loose enough to slip over your dog’s head.

Check the fit regularly, particularly for growing puppies or dogs whose weight or coat changes throughout the year.

2. How to measure your dog’s chest

Chest girth is one of the most important measurements for dog harnesses and clothing.

Find the widest or deepest part of your dog’s ribcage, usually just behind the front legs. Pass the tape underneath the chest and bring it around the body until the ends meet at the top.

Check that:

• The tape is level rather than angled

• It is not sitting in your dog’s armpits

• It lies close to the coat without digging in

• Your dog is standing naturally and breathing normally

Do not rely on weight or breed alone when choosing a size. Two dogs of the same breed and weight can have very different chest shapes and proportions.

3. How to measure your dog’s back length

Ask your dog to stand with their head in a natural position.

Place the end of the tape at the base of the neck, around the point where the neck meets the shoulders. Run the tape along the spine to the base of the tail.

Do not measure from the collar itself if it sits high on the neck, and do not include the length of the tail.

Back length is especially important for dog coats, shirts and rainwear. A garment that is too short may not provide the intended coverage, while one that is too long could interfere with movement or toileting.

How to measure your dog for a harness

Most harness size guides use the neck and chest measurements, although the precise measuring points depend on the harness design.

Begin with the chest girth, then check the neck measurement against the same size. Your dog should sit comfortably within both ranges rather than fitting one measurement but falling outside the other.

Once fitted, a harness should:

• Lie flat without twisting

• Remain secure when your dog changes direction

• Sit away from the sensitive armpit area

• Allow the shoulders and front legs to move freely

• Show no signs of rubbing or pressing into the skin

Dogs Trust advises that you should be able to fit a finger comfortably between the harness straps and your dog’s body while ensuring the harness does not move out of position or allow your dog to slip free.

Our Sheep Tweed Harness has four points of adjustment, allowing the fit to be refined across different body shapes. Begin with accurate measurements, then adjust each strap gradually once the harness is on your dog.

How to measure your dog for a collar

For a collar, measure the circumference of the neck where the collar will naturally sit.

Compare this measurement with the adjustment range shown on the product page. Ideally, your dog’s measurement should sit comfortably within the range rather than at its very smallest or largest limit.

After fastening the collar, use the two-finger check and make sure it cannot slide over your dog’s head. Recheck it after your dog has moved around, as posture and coat can affect how the fit feels.

How to measure your dog for clothing

For dog shirts, coats and rainwear, take all three measurements:

1. Neck circumference

2. Chest girth

3. Back length

Chest measurement will often determine the overall size, while back length helps you check the coverage and proportions. Neck measurement ensures the garment does not feel restrictive around the collar area.

Once your dog is dressed, check that they can walk, turn, sit and lie down naturally. The garment should not pull across the chest, restrict the shoulders or gather excessively around the legs.

Explore our dog clothing and apparel, including The Linen Shirt and our lightweight outerwear.

Measuring a miniature dachshund

Miniature dachshunds have wonderfully distinctive proportions: longer backs, shorter legs and often a relatively deep chest. This means that standard dog clothing may fit around the chest but provide too little back coverage, or offer the right length with excess fabric around the body.

Measure your dachshund in the same three places, paying particular attention to:

• The full back length from the base of the neck to the base of the tail

• The widest part of the chest

• Clearance around the front legs

• The distance between the garment and the ground

Willow & Woof’s Miniature Dachshund Wardrobe has been developed with longer bodies, shorter sleeves and carefully adjusted proportions in mind.

What should you do if your dog is between sizes?

If your dog’s measurements fall between two sizes, we generally recommend choosing the larger size. This allows greater comfort and freedom of movement, particularly for dogs with broader chests or thicker coats.

However, the best choice can depend on the product and your dog’s proportions. Consider:

• Whether the item is adjustable

• Whether the fabric has any stretch

• Whether the design is intended to be relaxed or closely fitted

• Whether your dog is still growing

• Which measurement falls outside the smaller size

Never choose a smaller size simply because of the letter on the label. Product sizing is not universal, and your dog may wear different sizes across different brands or designs.

If you are uncertain, contact our team with your dog’s breed, neck, chest and back measurements. We will be happy to help.

Common measuring mistakes to avoid

Choosing by breed alone

Breed suggestions can be helpful, but they are never a substitute for measuring. Individual dogs can differ significantly in build, coat and proportions.

Using your dog’s weight as the main guide

Weight does not tell you whether your dog has a broad chest, slender neck or longer back. Use it only as supporting information where requested.

Measuring while your dog is sitting

Sitting changes the shape of the chest and shortens the topline. Ask your dog to stand naturally for each measurement.

Pulling the tape too tightly

The tape should sit close to the body without compressing the coat or skin. A measurement that is too tight can lead to an uncomfortable size choice.

Adding extra room yourself

Unless the size guide says otherwise, record your dog’s actual body measurement. The intended ease and adjustment should already be reflected in the product’s sizing.

Assuming one measurement will fit every product

Always revisit the individual size guide before ordering. A harness, collar and raincoat may each use different measurements or fit in different ways.

How often should you measure your dog?

Measure puppies regularly while they are growing and check the fit of their walking accessories frequently.

Adult dogs should also be remeasured from time to time. Changes in weight, muscle tone, coat thickness or age can all affect fit. It is worth measuring again whenever you purchase a new design rather than relying on an old size.

Frequently asked questions

What measurements do I need for dog clothing?

Most dog clothing requires your dog’s neck circumference, chest girth and back length. Check the individual product guide because some designs may prioritise one measurement over another.

Where is the widest part of a dog’s chest?

The widest part is usually around the deepest section of the ribcage, just behind the front legs. Keep the tape level and make sure it does not sit inside the armpits.

How tight should the tape measure be?

The tape should sit smoothly against your dog’s coat without pulling, compressing the body or hanging loosely. Record the true measurement rather than adding your own allowance.

Should I measure my dog with their collar on?

It is generally easier to take a neck measurement without the collar. Measure the point where the collar naturally sits, unless the product guide gives different instructions.

Can I use my dog’s current harness as a size guide?

An existing harness can provide a useful reference, but body measurements are more reliable. Harness shapes and sizing methods vary, so always compare your dog’s current measurements with the new product’s guide.

A considered fit for everyday adventures

Taking a few quiet moments to measure your dog can make dressing for the next adventure much simpler.

Whether you are choosing a walking harness for country paths, a collar for everyday wear or clothing for changing British weather, comfort should always come first. Measure carefully, follow the individual product guide and check the fit again once the piece arrives.

Because thoughtful design is at its best when your dog can move, explore and enjoy it.

Discover the Willow & Woof collections.