Crate size calculator
Measure the dog, not the room. Put in two measurements, or pick the breed, and this gives the internal crate size you need and the standard size that matches it. Size it for the adult dog and use a divider while the puppy is small, and you buy one crate instead of three.
Measure the adult dog if you have one, and the expected adult dog if you do not. A crate bought to fit an eight week old puppy is outgrown in about a month. A crate bought for the adult, with the divider pushed forward, is right for both.
The rule
A crate has to let the dog stand up without ducking, turn around, and lie down fully stretched out on its side. The US federal animal welfare regulations put the same idea in legal language for kennels: an enclosure must provide sufficient space to allow each dog to turn about freely, to stand, sit, and lie in a comfortable, normal position, and to walk in a normal manner. For transport the wording is enough space to turn about normally while standing, to stand and sit erect, and to lie in a natural position. PetMD adds the practical version for owners: the dog should stand up with ease, fit through the door effortlessly, comfortably turn around, have at least 2 inches of clearance above the head when sitting, and be able to fully extend its limbs when lying on its side.
From 9 CFR 3.6(a)(2)(xi) and 9 CFR 3.16(e)(1), USDA Animal Welfare Regulations, plus PetMD reviewed by Jennifer Coates, DVM. Source.
How to measure
| Measurement | How |
|---|---|
| Length | With the dog standing on all fours, measure from the tip of the nose to the base of the tail. Do not include the tail itself. Add 2 to 4 inches. Source |
| Height | With the dog in a sit, measure from the floor to the top of the head. For upright eared breeds measure to the ear tips instead. Add 2 to 4 inches. Source |
| Headroom check | The regulatory minimum for a kennel is that interior height is at least 6 inches higher than the head of the tallest dog in the enclosure when it is in a normal standing position. PetMD's owner facing version is at least 2 inches of clearance above the head when the dog is sitting. Use whichever is larger for your dog. Source |
| Floor space, regulatory minimum | The US federal formula for licensed kennels: find the mathematical square of the sum of the length of the dog in inches, measured from the tip of its nose to the base of its tail, plus 6 inches, then divide the product by 144. That gives the minimum floor space in square feet. A dog measuring 24 inches needs (24 + 6) squared divided by 144, which is 6.25 square feet. Source |
| Width | You do not need to measure your dog's width. Crate width follows from the length and height of the crate you choose. Source |
The sizes actually sold
Crates are sold in a handful of standard lengths. This is a guide to what each one fits, not a product recommendation, and Puplr does not quote prices.
| Size | Inches | Centimetres | Suits | Typical dogs |
|---|---|---|---|---|
| 18 inch | 18 x 12 x 14 in | 46 x 30 x 36 cm | 0 to 2.7 kg | Toy breed puppies |
| 22 inch | 22 x 14 x 16 in | 56 x 36 x 41 cm | 2.7 to 5.4 kg | Chihuahua, Maltese, Yorkshire Terrier, Pomeranian |
| 24 inch | 24 x 18 x 20 in | 61 x 46 x 51 cm | 5.9 to 11.3 kg | Shih Tzu, Bichon Frise, Havanese |
| 30 inch | 30 x 20 x 23 in | 76 x 51 x 58 cm | 11.8 to 18.1 kg | Beagle, French Bulldog, Boston Terrier, Corgi |
| 36 inch | 36 x 24 x 26 in | 91 x 61 x 66 cm | 18.6 to 31.8 kg | English Bulldog, Bull Terrier, Australian Cattle Dog, Pit Bull Terrier |
| 42 inch | 42 x 28 x 30 in | 107 x 71 x 76 cm | 32.2 to 40.8 kg | Labrador Retriever, Golden Retriever, Boxer |
| 48 inch | 48 x 30 x 32 in | 122 x 76 x 81 cm | 40.8 to 49.9 kg | Bernese Mountain Dog, German Shepherd, Rottweiler |
Size bands from PetMD dog crate sizing chart, by Rebecca Bermingham, CVT, reviewed by Jennifer Coates, DVM, updated 10 October 2023. Inches and pounds are as published, the centimetre and kilogram figures are Puplr's conversions. This is a general guide to the sizes commonly sold, not a product recommendation, and Puplr sells nothing. PetMD's own caveat applies: base the size of the crate on your dog's measurements, and not their weight or breed alone.. Source.
How long a puppy can be crated
These are ceilings for a crated puppy who is awake and alone, not targets. No welfare body reached in this pass publishes a maximum crate time for an adult dog, so Puplr does not print one. What HSUS does say is that a dog who is crated all day and night does not get enough exercise or human interaction and can become depressed or anxious, and that a dog should not spend most of its time in a crate.
| Age | At a stretch | Source |
|---|---|---|
| 2 months | 2 hours | VCA Animal Hospitals, how to potty train your puppy. Take your puppy outside every 2 hours at 6 to 8 weeks of age, with overnight breaks as well Source |
| 3 months | 3 hours | VCA Animal Hospitals. For every month of age you can add an additional hour, so a 3 month old should be able to wait 3 hours Source |
| 4 months | 4 hours | VCA Animal Hospitals, one hour per month of age Source |
| 5 months | 4 hours | Humane World for Animals, formerly the Humane Society of the United States. The per month rule would give 5 hours here, but HSUS caps puppies under 6 months at three or four hours at a time, so Puplr holds at 4 Source |
| 6 months | 4 hours | Humane World for Animals. Puppies under 6 months of age shouldn't stay in a crate for more than three or four hours at a time. They can't control their bladders or bowels for that long, even during potty training Source |
Getting it right
- Buy for the adult dog and use a divider. HSUS says if your dog is still growing, choose a crate size that will accommodate their adult size, and PetMD says to buy for the expected adult size and move a removable divider back as the puppy grows
- If your crate has no divider, block off the back with a large box, per Preventive Vet
- Too big is a real problem for toilet training. VCA: if they have too much extra space, they may turn half of the crate into their bathroom. With an appropriately sized crate they become reluctant to eliminate in their bedding
- Too small is also a problem. PetMD says if any of the fit checks are too tight, go up a size, because not having enough space can create negative feelings about the crate
- Account for bedding. A crate mat or dog bed takes up space you measured for the dog
- Never use the crate as punishment. HSUS says crates should never be used for punishment, and a dog used incorrectly crated can feel trapped and frustrated
- Leave the door open when you are home so the crate stays a place the dog chooses
- Put it where the family is, not in an isolated room, and teach children not to poke fingers through the bars or disturb the dog inside
- Go straight outside after crate time. VCA points out that immediately going outside after time in the crate is a good way to encourage elimination in the right place
- Take the crate out of the plan if it is not working. HSUS is explicit that for some dogs crates will not be an option, and offers a tether in the bedroom as an alternative for night time
- Crate training pays off away from home. AVSAB notes that puppies used to being crated will be less stressed if they have to be hospitalised or confined for travel
Common questions
What size crate does my dog need?
Measure rather than guess. Nose to base of tail plus 2 to 4 inches gives the length. Floor to the top of the head while sitting plus 2 to 4 inches gives the height. Then pick the smallest standard crate that clears both numbers. PetMD is clear that weight and breed recommendations give only an estimate, because each dog is an individual.
Is a bigger crate kinder?
Not while you are toilet training. VCA explains the mechanism: with too much extra space a puppy may turn half of the crate into its bathroom, whereas in an appropriately sized crate it becomes reluctant to eliminate in its own bedding. Buy for the adult size and shrink the usable space with a divider.
How do dividers work?
You buy one crate sized for the adult dog and move a panel back as the puppy grows, so the living space stays just big enough at every stage. Most wire crates include one. If yours does not, Preventive Vet suggests blocking the back section with a large box.
How long can a puppy stay in a crate?
Roughly an hour per month of age for bladder control, per VCA: outside every 2 hours at 6 to 8 weeks, and for every month of age you can add an additional hour, so a 3 month old should manage 3 hours. HSUS puts a hard ceiling over the top of that: puppies under 6 months should not be crated for more than three or four hours at a time, because they cannot control their bladders or bowels for that long.
Is the one hour per month rule real?
Yes, and it is traceable. VCA Animal Hospitals publishes it in that form on its puppy potty training page. It is a guide to bladder capacity rather than a licence to crate a 6 month old for six hours, and HSUS caps under six month puppies at three or four hours regardless.
Is there a legal minimum crate size?
There is in the United States, for licensed kennels and dealers rather than for pet owners. 9 CFR 3.6 requires floor space equal to the square of the dog's nose to tail base length in inches plus 6 inches, divided by 144, in square feet, and an interior height at least 6 inches higher than the head of the tallest dog when standing normally. It is a useful sanity check on a crate you are about to buy.
Where should the crate go?
Somewhere calm but not isolated. HSUS suggests an area where the family spends a lot of time for the introduction, then a calm part of the home where the dog can relax without constant stimulation or noise, with a comfortable bed inside and the door left open when you are home.
Claims we could not source
These come up constantly and none of them could be traced to a veterinary or welfare organisation, so they are not used anywhere on this page.
- A maximum crate time for adult dogs. The often quoted 4 to 5 hours a day for an adult dog is widely attributed to the Humane Society of the United States, and it is not on the crate training page. The page says only that a dog crated all day and night can become depressed or anxious, and that a dog should not spend most of its time in a crate. Puplr does not publish an adult ceiling.
- The claim that a puppy should not be crated for longer than its age in months plus one hour. That phrasing is everywhere and it is not on any page reached in this pass. The traceable version is VCA's one additional hour per month of age, which is about bladder capacity rather than crate time, and Puplr labels it that way.
- Exact inches to add for crate length and height from a welfare body or veterinary association. The 2 to 4 inch figures come from Preventive Vet and the 2 inch head clearance from PetMD. The only margins in any regulation are the USDA's 6 inches, which apply to licensed kennels rather than to a pet crate in a living room.
- A crate size chart from a welfare body or kennel club. None exists in text form. The MidWest Homes for Pets chart is published as an image only, and the sizes Puplr lists come from PetMD instead.
- Royal Kennel Club crate training guidance. thekennelclub.org.uk redirects to royalkennelclub.com and the crate training page returned 404.
- RSPCA Australia crate guidance. Every candidate knowledge base URL returned 404 in this pass.
- A UK or Australian legal minimum crate size for pet dogs. Only the US federal kennel standards were found, and they apply to licensed dealers and exhibitors, not to owners.
Where the sources disagree
- The sizing rule itself is worded three different ways. USDA regulations for kennels say turn about freely, stand, sit, and lie in a comfortable, normal position, and walk in a normal manner. USDA transport regulations drop the walking and say turn about normally while standing, stand and sit erect, and lie in a natural position. HSUS gives owners the shortest version, large enough for your dog to stand up and turn around in, with no mention of lying down. PetMD gives the fullest owner facing version including full limb extension. Puplr uses the fuller version because a crate a dog cannot stretch out in is not big enough.
- How much to add. Preventive Vet says 2 to 4 inches on both length and height. PetMD says at least 2 inches of clearance above the head when sitting. USDA says 6 inches above the standing head for kennels. Three different margins for the same job.
- Time limits. VCA's one hour per month rule and the HSUS three to four hour ceiling cross over at about 4 months. Puplr caps at 4 hours from 5 months rather than letting the per month rule run on.
- Oversized crates. VCA and PetMD both warn that a too large crate undermines house training. HSUS does not raise the point at all and simply says to buy for adult size. The mechanism, that a dog is reluctant to soil its own bedding but will happily use the far end of a large crate, comes from VCA.
Next
Sources
- USDA APHIS, Animal Welfare Act and Animal Welfare Regulations, APHIS 41-35-076, sections 3.6 and 3.16: https://www.aphis.usda.gov/sites/default/files/AC_BlueBook_AWA_508_comp_version.pdf
- Michigan State University College of Law, Animal Legal and Historical Center, 9 CFR Part 3 Subpart A text: https://www.animallaw.info/administrative/us-awa-subpart-specifications-humane-handling-care-treatment-and-transportation-dogs
- Humane World for Animals, formerly the Humane Society of the United States, Crate training 101: https://www.humaneworld.org/resources/crate-training-101
- VCA Animal Hospitals, how to potty train your puppy: https://vcahospitals.com/pediatric/puppy/behavior-training/how-to-potty-train-your-puppy
- VCA Animal Hospitals, crate training and confinement for puppies and dogs: https://vcahospitals.com/know-your-pet/crate-training-your-dog---an-overview
- PetMD, how to choose the right crate size for your dog or puppy, reviewed by Jennifer Coates, DVM: https://www.petmd.com/dog/general-health/crate-sizing-for-dogs
- Preventive Vet, how to measure and choose a dog crate: https://www.preventivevet.com/dogs/how-to-measure-and-choose-a-dog-crate
- RSPCA UK, taking your pet on holiday, on container size for travel: https://www.rspca.org.uk/adviceandwelfare/pets/general/holiday
- AVSAB Position Statement on Puppy Socialization, on confinement training: https://avsab.org/wp-content/uploads/2018/03/Puppy_Socialization_Position_Statement_Download_-_10-3-14.pdf
- MidWest Homes for Pets, what size crate should I get, on measuring and dividers: https://www.midwesthomes4pets.com/resources/cratesizing/
Last reviewed 2026-09-06.