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Quick answer
An adult Bulldog usually measures about 60–80 cm (our estimate)1,2 around the chest and weighs 23–25 kg3.
These are the sizes most adult Bulldogs need. Your dog may differ, so measure to be sure.
Get an exact size for your dogHow a Bulldog is built, and why it matters for fit
The UK breed standard gives a weight of 25 kg for dogs and 23 kg for bitches3. That is a lot of dog on short legs, and most of the width is at the front.
Bailey & Coco says most adult Bulldogs wear its Large or XL2. There is no published chest range for the breed, so our figure of 60–80 cm is an estimate based on those size recommendations1.
Bulldogs are flat-faced (brachycephalic). The RSPCA advises walking flat-faced dogs on a harness rather than a collar, and warns that they can struggle in the heat4.
How to measure your Bulldog, step by step
- Get a soft tape measure, or a piece of string and a ruler. Stand your dog on a level floor with all four feet square underneath it.
- Find the measuring point: the widest part of the ribcage, just behind the front legs5. Julius-K9 asks you to measure a set distance behind the front legs, which depends on the size: two finger-widths for the Baby sizes, three for Mini-Mini and Mini, and four for size 0 and up6.
- Wrap the tape all the way round. Keep it flat and untwisted, snug against the body but not squeezing. Read the number in centimetres where the end meets the tape.
- Measure twice5. If the two readings differ, use the larger one.
- Weigh your dog too. Julius-K9 gives a weight range for every size as a second guide6; the other brands here size by chest only.
Bulldog measuring tips
- Measure around the widest part of the chest, just behind the front legs. On a Bulldog this is well forward.
- Measure the base of the neck too. A Bulldog's neck is thick, so check an overhead harness will go over the head.
- Keep the tape and every strap clear of the throat.
Want every detail, including neck, back length and weighing at home? Read our complete guide to measuring your dog.
Bulldog harness size by brand
Each brand cuts its sizes differently, so the same dog can be a different size, or a different letter, in each. Here is how a typical adult Bulldog fits each chart, and why.
Julius-K9
IDC Powerharness
Julius-K9 lists a chest range and a weight range for every size6. Chest girth is the main guide; we use weight to choose between two sizes when the chest fits both.
- A smaller Bulldog (chest 60 cm, 23 kg): size 0 (also fits Mini)
- A typical Bulldog (chest 70 cm, 24 kg): size 0 (also fits 1)
- A larger Bulldog (chest 80 cm, 25 kg): size 1 (also fits 2)
Overlaps in the Bulldog range: 60–67 cm: sizes Mini and 0 both fit; 63–76 cm: sizes 0 and 1 both fit; 71–80 cm: sizes 1 and 2 both fit.
Sizes overlap by design; chest girth is the main guide, weight is secondary.
| Size | Chest | Weight |
|---|---|---|
| Baby 1 | 29–36 cm | 0.8–3 kg |
| Baby 2 | 33–45 cm | 2–5 kg |
| Mini-Mini | 40–53 cm | 4–7 kg |
| Mini | 49–67 cm | 7–15 kg |
| 0 | 58–76 cm | 14–25 kg |
| 1 | 63–85 cm | 23–30 kg |
| 2 | 71–96 cm | 28–40 kg |
| 3 | 82–115 cm | 40–70 kg |
| 4 | 96–138 cm | 70–90 kg |
Highlighted rows are the sizes typical adult Bulldogs need.
Check price on AmazonRuffwear
Front Range Harness
Ruffwear sizes the Front Range Harness by chest girth only7, so your tape measure is all you need.
- A smaller Bulldog (chest 60 cm): size S
- A typical Bulldog (chest 70 cm): size M
- A larger Bulldog (chest 80 cm): size M
Sized by chest girth only.
| Size | Chest |
|---|---|
| XXS | 33–43 cm |
| XS | 43–56 cm |
| S | 56–69 cm |
| M | 69–81 cm |
| L/XL | 81–107 cm |
Highlighted rows are the sizes typical adult Bulldogs need.
Check price on AmazonBailey & Coco
Trail & Glow Harness
Bailey & Coco sizes the Trail & Glow Harness by chest girth only8, so your tape measure is all you need.
- A smaller Bulldog (chest 60 cm): size M (also fits S, L)
- A typical Bulldog (chest 70 cm): size L (also fits M)
- A larger Bulldog (chest 80 cm): size XL (also fits L)
Overlaps in the Bulldog range: 60–66 cm: sizes S and M both fit; 60–71 cm: sizes M and L both fit; 71–80 cm: sizes L and XL both fit.
Very adjustable, so neighbouring sizes overlap a lot. Sized by chest girth only.
| Size | Chest |
|---|---|
| XXS | 22–41 cm |
| XS | 26–50 cm |
| S | 35–66 cm |
| M | 40–71 cm |
| L | 55–83 cm |
| XL | 71–99 cm |
Highlighted rows are the sizes typical adult Bulldogs need.
Check price on AmazonPuppies and growing dogs: when to re-measure
Bulldog puppies fill out through the chest and shoulders as they grow. Bailey & Coco says many start in its Medium and move up to Large or XL as adults2.
The largest study of puppy growth so far, based on records from over 6 million young dogs, grouped dogs by adult weight: under 6.5 kg, 6.5–9, 9–15, 15–30 and 30–40 kg9. An adult Bulldog at 23–25 kg falls in the 15–30 kg group.
Size a puppy on its chest measurement today, not on the size you expect it to reach5. A harness bought to "grow into" is loose now, and a loose harness slips, rubs and is easier to back out of.
While your puppy is growing fast, we suggest measuring its chest every two weeks, then monthly until it stops changing. A quick check in between: if you can no longer slide two fingers under the straps, measure again.
Most harnesses adjust over a good part of their range, so a growing puppy may stay in one size for a while. When your puppy's chest reaches the top of its size's range, move up.
If your Bulldog is between two sizes
Brand charts often overlap, so a chest measurement can fall inside two sizes. Here is where that happens for a typical adult Bulldog:
- Julius-K9: 60–67 cm: sizes Mini and 0 both fit; 63–76 cm: sizes 0 and 1 both fit; 71–80 cm: sizes 1 and 2 both fit.
- Ruffwear: no overlapping sizes in this range.
- Bailey & Coco: 60–66 cm: sizes S and M both fit; 60–71 cm: sizes M and L both fit; 71–80 cm: sizes L and XL both fit.
How to choose:
- Our size finder picks the size where your dog's measurement sits nearer the middle of the range, so the harness can be adjusted either way.
- Ruffwear says that if your dog is right on the border between two sizes and fully grown, choose the larger size7. For a growing puppy that is truly between sizes, Ruffwear also suggests the larger one5.
- For Julius-K9, check the weight ranges too: if your dog's weight only fits one of the two sizes, go with that one6.
- Deep-chested dogs with a narrow waist can slip a loose harness, so if the larger size would only just fit on its tightest setting, the smaller one is usually safer.
Fit checks when the harness arrives
Two-finger rule
You should be able to slide two fingers flat under every strap, and no more7. Tighter than that can rub; looser can slip.
Strap behind the front legs
The strap around the body should sit a little way behind the front legs, not pressed up into the "armpit", where it will rub as your dog walks.
Nothing on the throat
Every strap at the front should sit on the breastbone or low on the chest, not across the throat.
Free shoulders
Watch your dog walk and trot. Its stride should look the same as without the harness. A small study found harnesses can shorten how far the shoulder reaches forward10, so if the stride looks shorter, adjust the fit or try another style.
Check for rubbing
After the first few walks, look behind the front legs, under the chest and around the neck for redness or broken hairs. If you find any, loosen or reposition the harness. If the skin is sore, stop using it and ask your vet.
Escape test
With the harness on, gently pull the lead forwards, then backwards and upwards. The harness shouldn't slide over the shoulders or ribs. If it does, tighten it, or choose a design with an extra strap behind the ribcage.
Re-check after a week
Webbing and buckles can settle in the first few walks. Check the two-finger fit again after a week.
Harness styles that suit a Bulldog
Wide, padded Y-front harness
Spreads the load across a broad chest and keeps straps away from the throat.
Step-in harness
Avoids pulling a tight opening over a big head.
Breathable, lightweight materials
Flat-faced dogs can struggle in the heat4.
Be careful with
- Any strap across the throat.
- Thick padded vests in warm weather.
Common mistakes
- Buying by weight or height. A Bulldog is short, but its chest is big.
- Walking a Bulldog on a collar and lead instead of a harness4.
- Measuring the neck instead of the chest. Harness sizes are set by chest girth.
- Assuming a size letter means the same thing in every brand. A Medium in one brand can be a Large in another, so check each chart in centimetres.
- Buying a size up "to grow into" for a puppy.
A note on health
If your Bulldog breathes noisily, tires quickly or struggles on walks, talk to your vet. A harness helps take pressure off the neck, but it doesn't treat breathing problems.
Collar and ID tag: the UK rule
In the UK, a harness doesn't replace a collar. A dog in a public place must wear a collar with the owner's name and address on it, or on a tag or plate attached to it11. Many owners clip the lead to the harness and use the collar for ID.
Bulldog harness questions
What size harness does a Bulldog need?
An adult Bulldog usually has a chest of about 60–80 cm (our estimate) and weighs 23–25 kg3. That usually means Julius-K9 IDC Powerharness: sizes 0 or 1; Ruffwear Front Range Harness: sizes S or M; Bailey & Coco Trail & Glow Harness: sizes M to XL. Measure your dog's chest to get the exact size.
How do I measure my Bulldog for a harness?
Stand your dog square, then wrap a soft tape around the widest part of the chest just behind the front legs5. Keep it flat and snug and read it in centimetres. Measure twice. See our full guide to measuring your dog.
What size harness for a Bulldog puppy?
Size a puppy on its chest measurement today, not its expected adult size5. Measure every couple of weeks while it grows fast and move up a size when its chest reaches the top of the current size.
What if my Bulldog is between two harness sizes?
Why does my Bulldog need such a big harness?
Because a harness goes round the chest, and a Bulldog's chest is very broad for its height. Bailey & Coco says most adults wear its Large or XL2.
Should a Bulldog wear a harness or a collar?
Can my Bulldog wear a harness in hot weather?
Choose a light, breathable one and keep walks to cooler times of day. Flat-faced dogs can struggle in the heat4. If your dog seems distressed, stop and contact a vet.