Mastiff size chart: crate, harness & collar
What the published charts say for a Mastiff, across 19 harnesses, 6 crates and 7 collars. Every answer says how it was reached, and none of them replaces measuring your dog.
Note: Height: open-ended upper bound (e.g. "& up", "minimum", "over"): max is null.
Adult Mastiff
- Height at the shoulder
- Male 30 in and up76.2 cm and up
Female 27.5 in and up69.9 cm and up - Adult weight
- Male 160–230 lb72.6–104.3 kg
Female 120–170 lb54.4–77.1 kg - Chest girth
- 37.4–41.3 in95–104.9 cm
- Neck
- 25.6–31.5 in65–80 cm
AKC prints: “Height: 30 inches & up (male), 27.5 inches & up (female)”, “Weight: 160-230 pounds (male), 120-170 pounds (female)”.
Source: AKC breed page, checked Nov 4, 2026.
Source: TARIGS, "Size table for different breeds" (breed row: Mastiff; inch values as printed, converted by TARIGS from cm; not sex-specific), checked Nov 4, 2026. Girth is a published chart range, not a breed-standard measurement, and is not split by sex.
These are published breed figures, not your dog. Measure your dog — chest girth for a harness, neck for a collar, length and height for a crate.
Sized for a male Mastiff
Harness sizes
| Harnesses (19) | Size | How it was worked out |
|---|---|---|
| Julius-K9 IDC Powerharness | 2 to 4 (3 sizes) | by chest girthBetween sizes. Check the maker’s chart before you buy.Julius-K9’s sizes overlap, so one dog can fall in several. Measure your dog’s chest and check the maker’s chart. |
| Ruffwear Front Range Harness | L/XL | by chest girth |
| Ruffwear Flagline Harness | L/XL | by chest girth |
| Ruffwear Web Master Harness | L/XL | by chest girth |
| Kurgo Tru-Fit Smart Harness (quick release) | X-Large | by chest girth |
| PetSafe Easy Walk Harness | Large or Extra Large | by chest girthBetween sizes. The maker says: “If your dog is between two sizes, choose a size up.” |
| PetSafe Easy Walk 3 in 1 Harness | Large | by chest girth |
| Rabbitgoo ControlPro No-Pull Harness (ControlPro series) | XL | by chest girth |
| Blue-9 Balance Harness | L | by chest girth |
| 2 Hounds Design Freedom No-Pull Harness | 1" XXLarge | by chest girth |
| Wild One Classic Cushioned Dog Harness (with neck buckle) | L | by chest girth |
| Wild One Step-In Dog Harness | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Voyager (Best Pet Supplies) Step-In Air Pet Harness | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Gooby Comfort X Head-In Harness | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Puppia RiteFit Harness (PAJA-AC617) | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Puppia Soft Harness (PDCF-AC30) | XXL | by chest girth |
| Chai's Choice Outdoor Adventure Dog Harness (3M reflective) | XL | by chest girth |
| Embark Adventure No-Pull Harness | LARGE or XL | by chest girthBetween sizes. Check the maker’s chart before you buy. |
| Carhartt Training Dog Harness (Nylon Duck Training Harness, PH0341) | X-LARGE | by chest girth |
Where a size reads as a span, the breed’s published range reaches across that many of the maker’s sizes. This site shows the span rather than choosing one for you.
Crate sizes
| Crates (6) | Size | How it was worked out |
|---|---|---|
| MidWest Homes for Pets iCrate Single Door Folding Dog Crate | No size | by weightMidWest Homes for Pets lists no iCrate Single Door Folding Dog Crate size for over 110 lb. Check with MidWest Homes for Pets.MidWest Homes for Pets lists the outside of the box; the usable inside is smaller. |
| MidWest Homes for Pets LifeStages Single Door Dog Crate | No size | by weightMidWest Homes for Pets lists no LifeStages Single Door Dog Crate size for over 110 lb. Check with MidWest Homes for Pets.MidWest Homes for Pets lists the outside of the box; the usable inside is smaller. |
| Petmate Sky Kennel | No size | by weightPetmate lists no Sky Kennel size for over 125 lb. Check with Petmate. |
| Diggs Revol Collapsible Dog Crate | No size | by weightDiggs lists no Revol Collapsible Dog Crate size for over 90 lb. Check with Diggs. |
| Impact Dog Crates Collapsible Dog Crate | Sizes by measurement only | Impact Dog Crates publishes no dog weight. Use the crate calculator.estimated interior, about ½ in smaller than Impact’s exterior size (Impact’s own note) |
| Frisco (Chewy) Fold & Carry Single Door Collapsible Wire Dog Crate | No size | by weightFrisco (Chewy) lists no Fold & Carry Single Door Collapsible Wire Dog Crate size for over 110 lb. Check with Frisco (Chewy).Frisco (Chewy) lists the outside of the box; the usable inside is smaller. |
Every crate row above is by the maker’s weight guidance, because no published body length exists per breed. A crate is sized on the body: use the calculator below with your own measurements.
Collar sizes
| Collars (7) | Size | How it was worked out |
|---|---|---|
| Ruffwear Front Range Collar | 20"-26" | by neck girth |
| Blueberry Pet Classic Solid Color Adjustable Dog Collar | L | by neck girth |
| PetSafe Martingale Collar | No size | by neck girthThis breed's published neck girth falls outside every size this maker prints. |
| Max and Neo Martingale All Nylon Dog Collar | Large | by neck girth |
| Wild One Waterproof Dog Collar | No size | by neck girthThis breed's published neck girth falls outside every size this maker prints. |
| 2 Hounds Design Side Release (Buckle) Collar / Buckle Martingale | XL or XXL | by neck girthBetween sizes. Check the maker’s chart before you buy. |
| Carhartt Dog Collar | LARGE | by neck girth |
Sized for a female Mastiff
Harness sizes
| Harnesses (19) | Size | How it was worked out |
|---|---|---|
| Julius-K9 IDC Powerharness | 2 to 4 (3 sizes) | by chest girthBetween sizes. Check the maker’s chart before you buy.Julius-K9’s sizes overlap, so one dog can fall in several. Measure your dog’s chest and check the maker’s chart. |
| Ruffwear Front Range Harness | L/XL | by chest girth |
| Ruffwear Flagline Harness | L/XL | by chest girth |
| Ruffwear Web Master Harness | L/XL | by chest girth |
| Kurgo Tru-Fit Smart Harness (quick release) | X-Large | by chest girth |
| PetSafe Easy Walk Harness | Large or Extra Large | by chest girthBetween sizes. The maker says: “If your dog is between two sizes, choose a size up.” |
| PetSafe Easy Walk 3 in 1 Harness | Large | by chest girth |
| Rabbitgoo ControlPro No-Pull Harness (ControlPro series) | XL | by chest girth |
| Blue-9 Balance Harness | L | by chest girth |
| 2 Hounds Design Freedom No-Pull Harness | 1" XXLarge | by chest girth |
| Wild One Classic Cushioned Dog Harness (with neck buckle) | L | by chest girth |
| Wild One Step-In Dog Harness | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Voyager (Best Pet Supplies) Step-In Air Pet Harness | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Gooby Comfort X Head-In Harness | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Puppia RiteFit Harness (PAJA-AC617) | No size | by chest girthThis breed's published chest girth falls outside every size this maker prints. |
| Puppia Soft Harness (PDCF-AC30) | XXL | by chest girth |
| Chai's Choice Outdoor Adventure Dog Harness (3M reflective) | XL | by chest girth |
| Embark Adventure No-Pull Harness | LARGE or XL | by chest girthBetween sizes. Check the maker’s chart before you buy. |
| Carhartt Training Dog Harness (Nylon Duck Training Harness, PH0341) | X-LARGE | by chest girth |
Where a size reads as a span, the breed’s published range reaches across that many of the maker’s sizes. This site shows the span rather than choosing one for you.
Crate sizes
| Crates (6) | Size | How it was worked out |
|---|---|---|
| MidWest Homes for Pets iCrate Single Door Folding Dog Crate | No size | by weightMidWest Homes for Pets lists no iCrate Single Door Folding Dog Crate size for over 110 lb. Check with MidWest Homes for Pets.MidWest Homes for Pets lists the outside of the box; the usable inside is smaller. |
| MidWest Homes for Pets LifeStages Single Door Dog Crate | No size | by weightMidWest Homes for Pets lists no LifeStages Single Door Dog Crate size for over 110 lb. Check with MidWest Homes for Pets.MidWest Homes for Pets lists the outside of the box; the usable inside is smaller. |
| Petmate Sky Kennel | 48" | by weight |
| Diggs Revol Collapsible Dog Crate | No size | by weightDiggs lists no Revol Collapsible Dog Crate size for over 90 lb. Check with Diggs. |
| Impact Dog Crates Collapsible Dog Crate | Sizes by measurement only | Impact Dog Crates publishes no dog weight. Use the crate calculator.estimated interior, about ½ in smaller than Impact’s exterior size (Impact’s own note) |
| Frisco (Chewy) Fold & Carry Single Door Collapsible Wire Dog Crate | No size | by weightFrisco (Chewy) lists no Fold & Carry Single Door Collapsible Wire Dog Crate size for over 110 lb. Check with Frisco (Chewy).Frisco (Chewy) lists the outside of the box; the usable inside is smaller. |
Every crate row above is by the maker’s weight guidance, because no published body length exists per breed. A crate is sized on the body: use the calculator below with your own measurements.
Collar sizes
| Collars (7) | Size | How it was worked out |
|---|---|---|
| Ruffwear Front Range Collar | 20"-26" | by neck girth |
| Blueberry Pet Classic Solid Color Adjustable Dog Collar | L | by neck girth |
| PetSafe Martingale Collar | No size | by neck girthThis breed's published neck girth falls outside every size this maker prints. |
| Max and Neo Martingale All Nylon Dog Collar | Large | by neck girth |
| Wild One Waterproof Dog Collar | No size | by neck girthThis breed's published neck girth falls outside every size this maker prints. |
| 2 Hounds Design Side Release (Buckle) Collar / Buckle Martingale | XL or XXL | by neck girthBetween sizes. Check the maker’s chart before you buy. |
| Carhartt Dog Collar | LARGE | by neck girth |
Puppy?
Size for the adult and use a divider. A crate bought to fit a puppy is outgrown in weeks, and a crate with a spare end stops working as a den. Buy the adult size and move the divider back as the dog grows. A harness or collar is the opposite: buy for the dog you have now, because adult-sized straps slip on a puppy.
Is your dog a mix?
Mixes vary a lot. Measure your dog. A breed figure describes a published standard, and a mix is not held to one. Two dogs from the same litter can land two sizes apart on the same chart.
Measure your Mastiff
The tables above start from a published breed range. This starts from your dog. Crates need a body length and a standing height, plus 4 in of room.
Size your Mastiff
Enter what you have measured. Every answer below is the maker’s own published range against your number — a starting point, not a fitting.
Published range for the Mastiff: 37.4 to 41.3 in chest, 25.6 to 31.5 in neck (TARIGS, "Size table for different breeds").
Measure your dog and enter it. A published range is a range: the boxes below stay empty because the middle of a range is a number nobody published. Full Mastiff size chart
Where to put the tape. Leave a box empty and the answers that need it say so, rather than guessing.
Enter a measurement above to see what each maker's chart says.
Sizes come from each maker’s own published chart. Check the maker’s current chart before you buy: charts change, and nothing here is a guarantee of fit.
Common questions
- What size harness for a Mastiff?
- On the charts published by their makers, a Mastiff comes out at Julius-K9 IDC Powerharness 2 to 4 (3 sizes), Ruffwear Front Range Harness L/XL, Ruffwear Flagline Harness L/XL (by published chest girth), with 15 of 19 charts giving a size. Size labels are not comparable between brands, so read the range rather than the letter. Measure your dog's chest girth at the widest part of the rib cage and check it against the maker's own chart before you buy.
- What size crate for a Mastiff?
- By the makers' own weight guidance, a Mastiff comes out at no maker's weight guidance covers this breed, so measure instead. Weight is the rougher route: a crate is sized on the body. Measure your dog from the nose to the base of the tail and from the floor to the top of the head while standing, add 4 inches to each, and compare that with the crate's interior, not its outside.
- How big does a Mastiff get?
- An adult Mastiff is 30 in and up tall at the shoulder for males and 27.5 in and up for females, 160–230 lb for males and 120–170 lb for females. Published sizing charts give a chest girth of 37.4–41.3 in and a neck of 25.6–31.5 in. These are breed-standard ranges, not your dog: individual dogs sit outside them. Measure your dog.
Other giant breeds
Breeds in the same size group on this site. The group is worked out here from adult male weight; it is not an AKC category.
Compare every chart instead: harness size charts, crate size charts, collar size charts.