Dog Bed Size Guide for Large and Giant Breeds

By Charlie Scott's | Published: 2026-10-16

Category: Buying Guides

Measure your dog's nose-to-tail length and shoulder height, then add 8-12 inches of extra length. Here's how to match large and giant breeds to the right bed.

Quick answer

Measure your dog from the tip of the nose to the base of the tail while they lie stretched out, then add 8 to 12 inches. For giant breeds over 100 pounds, choose a bed at least 48 inches long with a flat, structured memory foam base rather than a soft-filled one. If your dog curls up tightly, a donut bed can work, but only if the inner sleeping area still fits their curled length with a couple of inches to spare.

How to measure your dog for a bed

Use a soft tape measure and get two numbers while your dog is relaxed on the floor. First, measure from the tip of the nose to the base of the tail with the dog lying flat and stretched out, not curled. Second, measure the widest point across the shoulders or hips. Add 8 to 12 inches to the length so your dog can shift position overnight without hanging off the edge. For width, add 4 to 6 inches.

If your dog sleeps curled in a tight ball, measure the curled length instead and add 4 to 6 inches. That number tells you the minimum inner sleeping area a donut bed needs. A raised outer ring takes up space, so the outer dimensions can be much larger than the usable centre.

Stretched-out length + 8 to 12 inches = minimum bed length for sprawlers
Curled length + 4 to 6 inches = minimum inner centre for donut beds
Shoulder or hip width + 4 to 6 inches = minimum bed width
Re-measure every 6 to 12 months for puppies and growing breeds

Why bed height and fill matter more for large breeds

A large dog puts more concentrated weight on a bed, so a thin or loosely filled base compresses quickly and leaves the dog resting on the floor. Crumbed memory foam distributes weight evenly and keeps a stable surface, which matters most for older dogs and dogs that need structured support. A protective inner lining also helps the foam hold its shape between washes.

Waterproof covers are not a luxury for large dogs. Bigger dogs carry more mud, drool, and damp coat back from walks, and a waterproof outer fabric keeps moisture from reaching the foam. If the cover is not waterproof, the foam can stay damp and lose structure over time.

Flat beds vs donut beds: match the shape to the sleeper

Watch where your dog settles at night. Dogs that stretch out flat, sprawl on their side, or change position often do best on a flat rectangular bed with a firm foam base. Dogs that lean into edges, tuck their nose, or circle before lying down usually settle faster on a donut bed with a raised padded ring.

For giant breeds, flat beds are usually the safer default because they offer more usable surface area for the money. A donut bed can still work for a giant breed that curls tightly, but check the inner centre measurement, not the outer diameter, before buying.

Decision rules for sizing a large or giant breed bed

Rule 1: Size for the stretched-out length: Measure nose to tail base with the dog lying flat and add 8 to 12 inches. If the bed is shorter than that number, your dog's hips or shoulders will hang off the edge. When in doubt, size up rather than down.
Rule 2: Choose foam structure over thickness claims: Look for crumbed or orthopaedic memory foam with a protective inner lining. Soft fibre fill compresses under heavy dogs and loses support faster. A structured foam base is the difference between a bed that lasts and one that flattens.
Rule 3: Match the shape to the sleep position: Sprawlers and side sleepers need a flat rectangular bed. Curlers and edge-leaners do better with a donut bed, but only if the inner centre fits their curled length plus 4 to 6 inches. Measure the sleeping area, not the outer frame.
Rule 4: Prioritise a waterproof or water-resistant cover: Large dogs bring in more moisture and dirt. A waterproof outer fabric keeps the foam dry and helps the bed hold its shape between washes. Waterproofing protects the foam, which protects the support.
Rule 5: Re-check the fit as your dog ages: Senior dogs often change sleep positions and may need more room or a firmer surface. Puppies of large breeds can outgrow a bed within months. Re-measure every 6 to 12 months.

Product facts that affect sizing and fit

Scruffs Harvard Water Resistant Memory Foam Dog Bed: The Scruffs Harvard Water Resistant Memory Foam Dog Bed uses crumbed memory foam with a protective inner lining and is suited to larger dogs, older dogs, and dogs that benefit from a more stable resting surface. A stable foam base is the key feature for heavy dogs that compress soft-filled beds. The water-resistant build also helps the foam stay dry between washes.
Ralph & Co Henley Waterproof Orthopaedic Memory Foam Pillow Dog Bed: The Ralph & Co Henley Waterproof Orthopaedic Memory Foam Pillow Dog Bed combines waterproof protection, orthopaedic memory foam support, and an open pillow design for dogs that like to stretch out. The open pillow shape gives sprawlers room to extend, while the waterproof outer fabric protects the foam from muddy walks and damp coats.
Lords & Labradors Velvet Donut Dog Bed: The Lords & Labradors Velvet Donut Dog Bed has a circular shape, a raised padded outer ring, and a deeply cushioned centre for dogs that curl up while sleeping. This shape suits dogs that lean into edges, but the usable sleeping area is the inner centre, so measure that rather than the outer diameter.

Who these beds fit best

Best for

Large and giant breed dogs that stretch out or change position overnight
Older dogs or heavy dogs that need a stable, structured memory foam surface
Owners who want a waterproof or water-resistant cover for muddy walks and damp coats

Not for

Dogs that curl into a tight ball and prefer a soft, enclosed donut shape
Puppies still growing rapidly, unless you plan to size up again within a year
Owners looking for a lightweight, low-cost bed with no foam structure