If you are wondering what size urn you need for your pet, the general rule is simple: allow one cubic inch of urn capacity for every pound your pet weighed as a healthy adult, then add a little extra room to be safe. A 12 pound cat needs at least 12 cubic inches, and a 60 pound dog needs at least 60. When in doubt, choose the slightly larger size. An urn with room to spare is never a problem, while one that is too small can add stress to an already tender day.
I am Tammy, and I make handmade ceramic pet urns in my small studio. Sizing questions are among the most common messages I receive, often sent late at night by someone who has just come home from the vet with a small sealed bag and no idea what comes next. So I wanted to gather everything I usually explain into one calm, practical place. If you would like to know a little more about me and why I do this work, you are welcome to visit our story.
How does pet urn sizing work?
Urn capacity is measured in cubic inches, and cremation ashes take up roughly one cubic inch for every pound of healthy body weight. It helps to use the weight your pet carried in good health rather than their weight at the very end. Illness often causes weight loss, but the volume of ashes reflects bone structure rather than final weight, so the healthy weight gives a truer estimate.
Here is the simple way I walk customers through it:
- Recall your pet's healthy adult weight in pounds. That number is your minimum capacity in cubic inches.
- Add a buffer of around 10 cubic inches so nothing ever feels forced.
- Check the urn's stated capacity, not just its outside height. Thick ceramic walls and curved shapes reduce the usable space inside.
- Remember that most crematoriums return ashes in a sealed bag, and that bag needs a little room too.
What size urn do I need for my dog?
Dogs vary so much in size that weight matters far more than breed. As a gentle guide: small dogs under 25 pounds usually rest comfortably in urns of 15 to 35 cubic inches. Medium dogs between 25 and 60 pounds generally need 35 to 70 cubic inches. Large dogs from 60 to 90 pounds are best served by 70 to 100 cubic inches, and giant breeds over 90 pounds need 100 cubic inches or more. If your dog was a mix or sat between categories, simply size up to the next range.
What size urn do I need for my cat?
Most adult cats weigh between 8 and 14 pounds, so an urn in the 15 to 25 cubic inch range is comfortable for nearly every cat, with space for the sealed bag and a small buffer. This is exactly the range I had in mind when I designed my 18cm cat-shaped urns and my sleeping cat urns, each one hand-painted stroke by stroke to match a cat's own coat from photos. My lucky cat urns and two-tone jar urns hold a similar capacity. For kittens or very petite cats, a smaller keepsake size can feel more fitting.
What if the urn I love seems too big or too small?
An urn that is a little large is nothing to worry about. Some families tuck in a bit of fur, a collar, or a small folded note alongside the ashes, and the extra room becomes part of the tribute. If an urn you love is too small, you can keep a portion of the ashes there as a keepsake and place the rest somewhere meaningful, or share them among family members who each want to keep their friend close.
For rabbits, hedgehogs, chinchillas, and other small companions, I make small urns shaped and painted like the animal itself, and custom sculpture commissions are always sized around the ashes they will hold. Whenever someone orders from me, I confirm the capacity against their pet's weight before any painting begins, so there are no surprises later. You can see examples of past pieces in the gallery.
Pet urn size FAQ
How many cubic inches of ashes will I receive?
Roughly one cubic inch per pound of your pet's healthy body weight. The exact amount varies a little with bone density and the crematorium's process.
Is it okay if the urn is bigger than the ashes need?
Yes, completely. Extra space is the safer choice, and it never looks or feels wrong once the urn is closed.
What size urn do I need for two pets together?
Add both healthy weights together, then add a buffer of 10 cubic inches or more. A companion urn for a 10 pound cat and a 12 pound cat would be around 32 cubic inches or larger.
Do the ashes have to stay in the plastic bag inside the urn?
That is entirely your choice. Many people keep the sealed bag inside the urn because it feels tidy and secure, and it makes any future move easier. There are more answers to common questions on my FAQ page.
If you are still unsure, please do not carry the maths alone. Send me your pet's weight and a photo, and I will gently suggest the right size and shape for them. You can read about how the process works on how custom orders work, and I will take care of the rest.