What size urn does a rabbit or guinea pig need?
Allow about one cubic inch of urn space per pound your pet weighed: roughly 5 cubic inches for a medium rabbit and 2 to 3 for a guinea pig. That's keepsake-urn size, and ashes typically weigh 3-5% of body weight[1].
By the Small Mammal Cremation Services editorial team · Updated September 24, 2026 · 4 min read · Sources
- Urn sizes for rabbits, guinea pigs, ferrets, chinchillas and hedgehogs
- Why the opening matters as much as the volume
- Materials and prices for small urns
The quick answer
How big an urn do you need for a small pet?
Use the industry rule of thumb: about one cubic inch of space for every pound your pet weighed[2], then round up a little. A 4.5 lb rabbit needs around 5 cubic inches; a 2.3 lb guinea pig around 2 to 3. Almost every urn sold as a "keepsake" or "small pet" urn is large enough, and a standard cat urn is usually much too big.
| Pet | Typical weight | Expected ashes | Urn capacity to look for |
|---|---|---|---|
| Guinea pig | about 1 kg (2.3 lb) | about 37 g (1.3 oz) | 3 to 5 cubic inches |
| Rabbit, dwarf breed | about 1 kg (2.2 lb) | about 35 g | 3 to 5 cubic inches |
| Rabbit, medium breed | about 2.1 kg (4.6 lb) | about 74 g (2.6 oz) | 5 to 10 cubic inches |
| Rabbit, giant breed | 5 to 7 kg (11 to 15 lb) | about 175 to 250 g | 15 to 20 cubic inches |
| Ferret | 0.6 to 2 kg | about 20 to 70 g | 3 to 8 cubic inches |
| Chinchilla | about 0.5 kg | about 18 g | 2 to 3 cubic inches |
| Hedgehog | 300 to 600 g | about 10 to 20 g | 1 to 3 cubic inches |
The ash figures are our estimates at around 3.5% of body weight, the benchmark from a study of human cremations that pet crematories adapt. For a pet rabbit of median UK weight we'd expect about 74 g[3], and for a median guinea pig about 37 g[4]. The urn size calculator does the arithmetic for your pet's exact weight.
Free tool
Urn size calculator
Find the urn volume you need from your pet's weight, plus keepsake and sharing options.
By species
Do ferrets, chinchillas and hedgehogs need different urns?
Mostly they need smaller ones. Ferrets vary a lot by sex: according to the Merck Veterinary Manual, males average about 2 kg and females about 1.2 kg[5], so a jill's ashes may barely cover the bottom of a rabbit-sized urn. African pygmy hedgehogs are smaller still, with adult males at 400 to 600 g[6], which leaves perhaps a tablespoon of ash.
For very small amounts, a tiny urn often feels right rather than a half-empty one. Heart-shaped keepsake urns, small hinged boxes and tealight-holder urns hold one to three cubic inches. Giant rabbit breeds are the exception: a Flemish Giant can need an urn closer to a cat's.
The detail people miss
Why check the urn's opening as well as its size?
Most ashes come home sealed in a small plastic bag inside a tin or box. Many families prefer to place that sealed bag straight into the urn rather than pour loose ash. That only works if the opening, or the lid or base panel, is wide enough for the bag to pass through.
- Top-opening urns with a wide screw or lift-off lid are easiest; ask for the opening diameter.
- Bottom-loading urns have a small panel underneath. They look tidy but some are too narrow for a bag.
- Keepsake urns with a threaded cap often have a very small hole meant for pouring with a funnel.
- Boxes with a sliding or hinged lid are the easiest of all for a small, soft bag.
Choosing a style
Which urn materials suit a small pet, and what do they cost?
Small urns cost far less than you might expect, because there's so little material. Keepsake or mini pet urns typically cost $15–$60[7], and a single keepsake urn averages about $28[8]. Full-size urns for cats and dogs cost more, but you won't need one.
| Material | Typical price | Good to know |
|---|---|---|
| Biodegradable (paper, bamboo, salt) | $15 to $80 | For burial or planting; not for keeping indoors long-term |
| Ceramic | $20 to $100 | Wide choice of colors; fragile if dropped |
| Wood | $30 to $150 | Warm look; hinged boxes are easy to fill |
| Metal (brass, pewter) | $40 to $200 | Durable; threaded lids seal well |
| Marble or stone | $80 to $300 | Heavy and lasting; check opening size |
Those ranges come from a US urn retailer's price guide: biodegradable $15–$80[9], ceramic $20–$100[10], wood $30–$150[11], metal $40–$200[12] and stone $80–$300[13]. Engraving a name usually adds a modest amount. The memorial budget planner adds the urn to the rest of the bill.
Where are (or will be) your pet's ashes?
Tap an answer to vote and see how others answered. Anonymous.
Bonded companions
Can you get one urn for a bonded pair?
Yes, and it's a lovely idea for rabbits or guinea pigs who spent their lives together. Buy an urn with room for both, so roughly double the single-pet capacity. Some families keep the first pet's sealed bag in the shared urn and add the second's when the time comes, which avoids mixing if you'd prefer not to.
If you'd rather the ashes are mixed, some providers will do a joint cremation when two pets die close together, or combine ashes later at your request. Our explainer on private vs communal cremation covers how joint cremation works, and the guide to bonded-pair survivor care is there for the partner who's still with you.
If the ashes will go outside
Which urn should you choose for burying or planting ashes?
For burying ashes in the garden or a planter, a biodegradable urn is the natural choice. Some are designed for planting: the Bios Urn for pets costs about $99[14] and includes a seed capsule, and the Living Urn's pet planting system about $119[15].
Be careful putting ashes right against roots. Cremated remains have a very high pH of about 11.7[16] and a lot of salt, which can harm plants. Planting urns include a soil amendment for this reason; if you're doing it yourself, mix the ashes with plenty of compost and place them a little away from the root ball. Our memorial ideas for small pets include planting ideas that suit a rabbit's favorite corner.
Want to share the ashes between an urn and a few keepsakes? Work out the amounts first with the ashes sharing planner, and see our keepsakes and jewelry guide for pieces that hold just a pinch. If you haven't arranged cremation yet, tell us about your pet and we'll email local options.
Reader polls
What would you choose?
Vote anonymously and see how other readers answered. The results are live counts from people who visit this site, so they show real opinions, not a scientific sample.
What would you most want to keep from your rabbit, guinea pig or ferret?
Tap an answer to vote and see how others answered. Anonymous.
Where are (or will be) your pet's ashes?
Tap an answer to vote and see how others answered. Anonymous.
How much would you spend on a memorial item, beyond the cremation itself?
Tap an answer to vote and see how others answered. Anonymous.
Free tools to help you plan
Urn size calculator
Find the urn volume you need from your pet's weight, plus keepsake and sharing options.
Ashes sharing planner
Split ashes fairly between family members, keepsake urns and jewelry.
Memorial budget planner
Add up cremation, urn, keepsakes and a farewell so the total holds no surprises.
Questions people ask
Can I use a cat urn for my rabbit?
You can, but it will usually be far too big. A 10 lb cat needs about 10 cubic inches, while a medium rabbit needs around 5 and a dwarf rabbit 2 or 3. A half-empty urn isn't a problem in itself, but a keepsake or small pet urn often looks and feels more fitting.
Do I have to transfer the ashes into the urn myself?
No. Some crematoria will place the ashes in an urn you supply or buy from them, often at no extra charge. If you do it yourself, keeping the ashes in their sealed bag is the simplest and least upsetting way. If you need to pour, use a paper funnel over a tray, on a calm day indoors.
What if the urn I love is too small?
You can split the ashes: fill the small urn and keep the rest in the original container, scatter them, or use a second keepsake. Many people find having more than one small memorial comforting. The ashes sharing planner shows how far your pet's ashes will go across several pieces.
How do I seal a small urn so it doesn't leak?
Threaded lids on metal urns seal well on their own. For ceramic, wood or bottom-loading urns, a thin line of clear silicone or a drop of craft glue around the lid or panel makes it permanent. Only seal it once you're sure you won't want to add or remove anything, such as a partner's ashes.
Is a biodegradable urn a good idea for keeping ashes indoors?
Not for the long term. Biodegradable urns are designed to break down in soil or water, and some soften in a humid room. If you're not sure yet whether you'll bury the ashes, keep them in a ceramic, wood or metal container for now and buy a biodegradable urn when you're ready.
Can I bury the urn in the garden?
Yes. A biodegradable urn returns to the soil; a ceramic or metal urn will last, which some families prefer so they can move it later. Choose a spot away from vegetable beds and water, and dig deep enough that it won't be disturbed by gardening or animals.
Sources and our estimates
- [1] Embrace notes cremated remains typically weigh about 3-5% of the pet's original body weight. Embrace Pet Insurance - Bury or Cremate Your Dog? Costs, Pros & Cons, 2025.
- [2] Using the industry rule of thumb of 1 cubic inch of urn space per pound of body weight, a 12 lb cat needs an urn of about 12 cubic inches; a 70 lb dog needs about 70 cubic inches. Our estimate: urn cu in = body weight lb x 1 (industry rule of thumb, not a measured value). How we calculate.
- [3] A median-weight adult pet rabbit (2.1 kg) would be expected to return about 74 g (2.6 oz) of cremated remains. Our estimate: 2,100 g x 3.5%. How we calculate.
- [4] A median-weight pet guinea pig (1.05 kg) would be expected to return about 37 g (1.3 oz) of cremated remains. Our estimate: 1,050 g x 3.5%. How we calculate.
- [5] Ferrets live about 6-10 years; males average about 4 lb (2 kg) and females 2.5 lb (1.2 kg). Merck Veterinary Manual - Table: Ferrets at a Glance.
- [6] African pygmy hedgehogs live an average of 4-6 years; adult males weigh 400-600 g and females 300-400 g. Merck Veterinary Manual - Overview of Hedgehogs.
- [7] Keepsake or mini pet urns cost about $15–$60, versus $25–$100 for small and $40–$200 for medium urns (Memorials.com). Memorials.com – Pet Urn Cost Guide, 2025.
- [8] A single keepsake urn costs around $28 and a set of six around $115, per U.S. Funerals Online figures cited by Funeral.com. Funeral.com – How Much Do Cremation Urns Cost in 2025, 2025.
- [9] Memorials.com's pet urn cost guide puts biodegradable pet urns at $15–$80. Memorials.com – Pet Urn Cost Guide, 2025.
- [10] Memorials.com puts ceramic pet urns at $20–$100. Memorials.com – Pet Urn Cost Guide, 2025.
- [11] Memorials.com puts wooden pet urns at $30–$150. Memorials.com – Pet Urn Cost Guide, 2025.
- [12] Memorials.com puts metal pet urns at $40–$200. Memorials.com – Pet Urn Cost Guide, 2025.
- [13] Memorials.com puts marble and stone pet urns at $80–$300. Memorials.com – Pet Urn Cost Guide, 2025.
- [14] The Bios Urn for pets, a biodegradable urn with a seed capsule, costs $99. Bios Urn – Pets, 2026.
- [15] The Living Urn's pet bio-urn planting system (without a tree) costs $119. The Living Urn – Pet tree urn, 2026.
- [16] Cremated remains have a very high pH of approximately 11.7, which is toxic to plants without amendment. Larkspur Conservation — Giving Cremated Remains a New Life Through Science, 2024.
Arrange cremation with the right urn
Tell us what you need and where you are. We'll reply by email with clear options and prices so you can decide in your own time.