Cremation Urn Sizes Explained: A Litre-by-Litre Guide
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Cremation urns in Australia are typically measured in litres (or sometimes cubic inches on international sites, though we always use litres here). As a simple guide: adult urns generally range from 3.5 to 4.5 litres, companion urns from 7 to 9 litres, and keepsake urns from a few millilitres up to around 0.5 litres. Getting the litre capacity right is the single most important sizing decision when choosing an urn.
Full litre-by-litre sizing table
| Urn type | Typical capacity | Best suited to |
|---|---|---|
| Keepsake urn | 0.05–0.5 litres | A small symbolic portion, shared among family |
| Infant / child urn | 0.5–2 litres | A baby or young child |
| Medium / small adult urn | 2.5–3.5 litres | A smaller-framed adult, or a partial amount of ashes |
| Standard adult urn | 3.5–4.5 litres | The full ashes of most adults |
| Companion urn (double) | 7–9 litres | Two people sharing a single urn |
How to work out what you need
- Check the weight of the ashes, if provided by the crematorium — roughly 1 kilogram of ashes takes up about 1 to 1.2 litres of volume.
- Decide whether the urn needs to hold the full amount, or just a portion (if some ashes are being divided into keepsakes or jewellery).
- Add a small buffer — choosing an urn slightly larger than the minimum required makes it easier to seal the lid properly and handle the ashes without spillage.
A note on measurements
Some overseas retailers list urn capacity in cubic inches rather than litres. As a quick conversion, 1 litre is approximately 61 cubic inches — but at Premium Urns, every product is listed in litres, so Australian customers can compare sizes easily without needing to convert.
Still not sure?
If you know the total weight of the ashes, our team can help you match it to the right capacity — or see our related guides on how much ash an adult typically produces and companion urn sizing.
Why getting the size right matters
Choosing an urn that's too small isn't just an inconvenience — it can mean the lid doesn't seal properly, increasing the risk of spillage or an unstable fit, and can make the whole process of transferring ashes more stressful than it needs to be. On the other hand, an urn that's dramatically oversized for the amount of ash it holds can shift and rattle inside, which some families find unsettling. Aiming for a capacity reasonably close to (but comfortably above) the actual volume of ashes tends to give the best result.
Sizing for unusual situations
Occasionally a family needs to size for something outside the standard adult range — for example, if ashes have already been partially divided elsewhere before reaching you, or if you're combining ashes from more than one source into a single urn. In these cases, it's worth physically measuring or weighing what you have (a kitchen scale and a knowledge of the 1kg-to-roughly-1.1-litre conversion goes a long way) rather than relying on the general averages in the table above.
How Premium Urns lists capacity
Every urn in our range lists its capacity clearly in litres on the product page, so you can compare options directly without needing to convert from another unit. If you're ever unsure which size is right for your situation, our team is happy to help you work it out before you order.
Frequently Asked Questions
What size urn do I need for one adult?
Most adults are comfortably accommodated by a standard adult urn with a capacity of 3.5 to 4.5 litres.
How many litres is a standard companion urn?
Companion (double) urns designed to hold the ashes of two people are typically 7 to 9 litres in capacity.
How do I convert cubic inches to litres for urn sizing?
One litre is approximately 61 cubic inches. Premium Urns lists all capacities in litres to make comparison straightforward for Australian customers.
What size urn is used for a small portion of ashes?
Keepsake urns, typically 0.05 to 0.5 litres, are designed to hold a small, symbolic portion rather than the complete ashes.
Is it better to choose a slightly larger urn than needed?
Yes, a small buffer above the minimum required capacity makes sealing the lid and handling the ashes easier and reduces the risk of spillage.
What happens if I order an urn that's too small?
If the ashes don't fit comfortably, the lid may not seal properly. Most retailers, including Premium Urns, allow an exchange for a larger size if the urn hasn't been used yet.
Do all urn retailers list capacity in litres?
Not always — some overseas retailers list capacity in cubic inches instead. Premium Urns lists every urn's capacity in litres, to make comparison straightforward for Australian customers.
At Premium Urns, we help Australian families find a memorial that feels right, without any pressure. Explore our full range of cremation urns online, or get in touch with our team if you'd like a hand choosing.
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