Pets · Updated October 27, 2026

Dog Bed Size Calculator: What Size Bed Does My Dog Need? (2026)

A bed that is too small forces your dog to stay curled up; one that is far too big can feel exposed. Enter a few measurements below to get a starting size, based on the sizing rules published by bed makers and pet-care guides I cite at the bottom of the page.

Dog bed size calculator

How it works: I add Majestic Pet’s allowance to your dog’s length (6–8 in for dogs under 26 lb, 8–10 in for 26–45 lb, 10–12 in above 45 lb, using the low end for curlers and the high end for sprawlers; 6–8 / 8–10 / 10–12 in by length if you skip weight), then pick the smallest standard size at least that long. If your dog’s weight points to a bigger size, I use the bigger one. The weight bands are my own mapping of Majestic Pet’s small/medium/large wording onto its weight chart.

Typical exterior bed sizes (chart)

These are typical exterior (outside) dimensions for standard rectangular beds, not sleeping areas, from Majestic Pet’s size guide. Sizes vary between brands, so always check the actual dimensions on the bed you’re considering. The last two columns show the longest dog (nose to base of tail) each size fits using the +6 in and +12 in rules; that’s my arithmetic, not the brand’s, and it only holds for flat beds whose sleeping area matches the outside size. Bolsters reduce the sleeping area.

How to measure your dog for a bed

1. Wait for nap time. Taylor & Tails says measuring is easiest while your dog is asleep, and CertiPUR-US says to measure in the sleeping position. If your dog sleeps stretched out, measure it stretched out.
2. Measure length. Run a soft tape from the tip of the nose to the base of the tail, where it meets the body. Don’t include the tail.
3. Add room to move. Add 6–12 inches. Majestic Pet uses 6–8 in for small dogs, 8–10 for medium and 10–12 for large; CertiPUR-US says 8–10 in.
4. Note how your dog sleeps. Curlers can use a round or donut bed; Majestic Pet suggests an inside diameter of at least the dog’s length plus 6 inches. Sprawlers need a rectangular bed with the full allowance.
5. Compare with the inside measurements. On bolster and donut beds, the sleeping area inside the bolsters is smaller than the outside size. Your number should fit inside.
6. Check the brand’s own guide. Some makers use a different rule (Kuranda adds 4 inches for its raised cot beds). For a specific bed, the maker’s chart wins.

When to size up

• Senior and arthritic dogs. Rover quotes vets who say dogs should be able to stretch or sleep in any natural position and change positions during the night. A stiff dog that can’t stretch out is uncomfortable. Pair the right size with supportive foam: AKC and CertiPUR-US both point older dogs with joint problems toward orthopedic beds. See my orthopedic beds for senior dogs.
• Sprawlers. Dogs that sleep flat on their side need the most length, so use the top of the allowance.
• Between two sizes. Majestic Pet and CertiPUR-US both say to round up, and Kuranda says not to size down.
• Still-growing puppies. Rover suggests either buying for the current size or sizing up for the expected adult size.

When not to go huge: Rover notes that a bed that is too big can make some dogs feel exposed. Anxious dogs that like to curl into a bolster may settle better in a snug donut or bolster bed sized by its inside diameter; see my calming dog beds for anxious dogs. Seniors with stiff joints also do better with low sides they can step over easily, and a dog ramp helps if their bed is on the couch or your bed.

Beds and gear for every size

• Best orthopedic dog beds for senior dogs
• Best calming dog beds for anxious dogs
• Best dog ramps for senior dogs

Share or embed this calculator

Pet bloggers, shelters, groomers and trainers are welcome to link to this calculator or reproduce the sizing chart, as long as you credit me with a link back to this page. Suggested credit:

<a href="https://bestbyniche.com/pets/dog-bed-size-calculator/">Dog bed size calculator</a> via BestByNiche

If you reuse the size chart, please credit Majestic Pet too.

Sources

• Majestic Pet — Dog bed size guide (add 6–12 in by dog size, standard size chart by weight, inside vs. outside dimensions, sleep styles)
• CertiPUR-US — How to choose a dog bed (measure in the sleeping position, add 8–10 in, sleeper types, orthopedic foam for older dogs)
• Kuranda — Dog bed size chart (nose to base of tail plus 4 in; don’t size down)
• Taylor & Tails — Bed sizing guide (measure while asleep, add 6–10 in / 15–25 cm)
• Rover — How to choose a dog bed (vets on room to change position, low sides for seniors)
• American Kennel Club — Choosing the right dog bed (supportive beds for joints, orthopedic beds)

I did not measure dogs or test beds myself. This calculator applies the published sizing rules listed above. Results are a starting point; every dog and every brand is different, so check the dimensions of the specific bed before buying.