Cat Tree Size Calculator
Perch width, step spacing, base footprint and post diameter from your cat's body length. Design a tree in 3D, score one you have found online, or plan a wall shelf route when the floor is full.
Enter your values
Results update instantly as you type.
Height follows your keenest climber, step spacing follows the cat who struggles most, perch size follows the biggest.
Everything is worked out in your browser, so the numbers never leave your device. The shareable link reopens the calculator with these values, and with your design if you have edited one.
Results
Working
- body length = 11 + 0.68 x 10 lb = 17.8 in
- everyday perch = 0.85 x 17.8 in = 16 in
- top perch = 1.20 x 17.8 in = 22 in
- scratching post = 1.60 x 17.8 in = 29 in
- step = 17.8 in x 1 (drive) x 1 (ability) = 18 in
- height = ceiling 96 in - 28 in headroom and reach = 68 in
- base = max(22 in + 6 in, 68 in x 0.5) = 34 in
- min weight = 1.2 x 10 lb x 68 in / 34 in = 24 lb
- surfaces needed = 2 x 1 cat + 1 = 3
Design it in 3D
Drag the background to orbit, drag a level to move it. Arrow keys nudge, shift for bigger steps, delete removes.
Quick answer
A cat tree is sized from body length, not from the cat's weight or the room's height. Perches need to be at least 85% of nose-to-tail-base length, steps no more than one body length apart, and the base at least 45 to 55% of the tree's height or it tips when the cat launches off the top.
perch = 0.85 x body length; step = body length; base = max(top perch + 6 in, height x 0.45-0.55)
Worked example
A 10 lb domestic shorthair, 18 in nose to base of tail, in a room with an 8 ft ceiling. The tree is a shape sold by the thousand: 52 in tall, 20 in base, five levels, 25 lb shipped.
| Dimension | Listed | Needs | Result |
|---|---|---|---|
| Overall height | 52 in | 68 in | tight |
| Base width | 20 in | 28 in | fails |
| Height to base ratio | 2.6:1 | 2.4:1 or lower | fails |
| Product weight | 25 lb | 32 lb | tight |
| Largest perch | 12 in | 16 in | fails |
| Top perch | 14 in | 22 in | fails |
| Average step | 10.5 in | 18 in or less | pass |
| Post diameter | 3 in | 3.5 in | tight |
| Unbroken sisal run | 22 in | 29 in | fails |
| Condo entry hole | dia 7 in | dia 8 in | fails |
| Resting surfaces | 6 | 3 | pass |
Score 32% — not right for your cats, keep looking. The height is fine and the price is usually fine. What fails is the base: at 2.6:1 height to base it needs an anchor, and the 22 in sisal run is broken by a platform rather than giving one unbroken stretch of 29 in. That combination is why a tree can look right in photographs and still end up ignored in the corner.
Working
- body length = 11 + 0.68 x 10 lb = 17.8 in
- everyday perch = 0.85 x 17.8 in = 16 in
- top perch = 1.20 x 17.8 in = 22 in
- scratching post = 1.60 x 17.8 in = 29 in
- step = 17.8 in x 1 (drive) x 1 (ability) = 18 in
- score = points scored / points available = 32%
Cat tree size by breed
Typical adult figures in a room with an 8 ft ceiling, one cat, average climbing habit. Measure your own cat where you can, since within any breed the spread is wide enough to change the answer.
| Breed | Weight | Body length | Perch | Top perch | Step | Height | Base | Post |
|---|---|---|---|---|---|---|---|---|
| Munchkin | 8 lb | 16.4 in | 14 in | 20 in | 14 in | 50 in | 26 in | 27 in |
| Siamese | 9 lb | 17.1 in | 15 in | 21 in | 22.5 in | 76 in | 38 in | 28 in |
| Domestic shorthair | 10 lb | 17.8 in | 16 in | 22 in | 18 in | 68 in | 34 in | 29 in |
| British shorthair | 12 lb | 19.2 in | 17 in | 23 in | 16.5 in | 50 in | 29 in | 31 in |
| Bengal | 12 lb | 19.2 in | 17 in | 23 in | 24 in | 76 in | 38 in | 31 in |
| Ragdoll | 16 lb | 21.9 in | 19 in | 27 in | 18.5 in | 50 in | 33 in | 36 in |
| Norwegian Forest | 15 lb | 21.2 in | 19 in | 26 in | 24 in | 76 in | 38 in | 34 in |
| Maine Coon | 18 lb | 23.2 in | 20 in | 28 in | 23 in | 68 in | 34 in | 38 in |
Post is the unbroken scratching run measured from the floor. Base is the minimum square footprint for a free-standing tree at that height.
At a glance
| What it does | Sizes a cat tree, scores one you found, or plans a wall shelf route |
|---|---|
| Category | Pets |
| Inputs needed | Cat weight or body length, life stage, climbing habit, ceiling height, floor space |
| Main output | Verdict, overall height and base footprint |
| Formula | perch = 0.85 x body length; base = max(top perch + 6, height x 0.45-0.55) |
| Cost | Free, no sign-up, no download |
How to use the Cat Tree Size Calculator
- Pick your cat's breed, or enter weight and measure nose to base of tail for a sharper answer.
- Add every cat that will share the tree. Sizing follows the biggest, the keenest and the least able separately.
- Enter ceiling height and the floor space the spot can take, then say where the tree goes.
- Read the verdict and the working, then open the designer to move levels, swap modules and change colours.
- Switch to Check a tree you found to score a listing, or Wall shelves if the floor is already full.
Frequently asked questions
How tall should a cat tree be?
Tall enough that the cat can stand up on the top perch with headroom to spare, which usually means ceiling height minus about 20 in for a keen climber. For a cat that mostly lounges, or a senior, 40 to 50 in with closely spaced steps gets used far more than a tower they never climb.
How wide does a cat tree perch need to be?
At least 85% of body length measured nose to base of tail, so an 18 in cat needs roughly a 16 in perch to loaf on. The top perch should be about 120% of body length so the cat can stretch out rather than balance.
How do I stop a cat tree from wobbling?
Wobble is a base problem, not a weight problem. The base should be 45 to 55% of the tree's height across, and the assembly should weigh at least 1.2 times cat weight times height divided by base width. Past 2.4 to 1 height to base, bracket it to a wall stud instead.
How many perches do I need for two cats?
Two surfaces per cat plus one, so five for two cats. Cats defend vertical routes, so a tall tree with one perch per level creates a bottleneck rather than shared space. Going wider usually beats going taller.
What size scratching post does my cat need?
The sisal run must allow a full standing stretch, about 1.6 times body length from the floor, and it has to be unbroken. Most trees split the post at the first platform, which is why cats go back to the sofa arm.
What size cat tree does a Maine Coon need?
Around a 27 in body length, which puts perches near 23 in, a top perch near 33 in, and a base near 40 in square. Almost nothing sold as a large cat tree is built to that base width, so a Maine Coon tree is one of the few cases where building beats buying outright.
Is it cheaper to build a cat tree than buy one?
Usually yes on materials, but the saving comes from getting dimensions a shop tree will not sell you, particularly base width and an unbroken scratching post. Compare on base width and perch size rather than on height, since height is the cheap part.
Results are estimates for general information. Sizing is built from feline body proportions and static stability, not veterinary advice. If your cat has a diagnosed joint or mobility condition, confirm safe heights with your vet.
Related calculators
- Cat Shelf Spacing Calculator
- Cat Age Calculator — coming soon
- Cat Calorie Calculator — coming soon