Urn size calculator
Urns are sold by capacity in cubic inches, and the rule is one cubic inch for each pound of body weight before cremation. Enter the weight and this gives you the capacity to buy, with a margin so it is not a near miss.
Enter a weight to see the capacity you need. The rule is one cubic inch of urn for each pound of body weight before cremation.
Sizing only. For what each material costs and your legal right to buy an urn anywhere rather than from the funeral home, see cremation urns and urn cost.
The rule, and why it works
One cubic inch of urn capacity for every pound of body weight before cremation. Someone who weighed 180 pounds needs about 180 cubic inches, and the standard adult urn holds 200, which is why that size fits most people. The rule works because what comes back is processed bone rather than tissue, and bone volume tracks body size closely enough for the purpose.
It is a rule of thumb rather than a measurement, so allow a margin. We add 10% and round up. Buying an urn slightly too large costs nothing and nobody notices. Buying one slightly too small is discovered by a family at the funeral home, on the day, with the ashes already there.
Urn size chart
| Capacity | Name | Suits |
|---|---|---|
| Under 5 cu in | Keepsake | A share for one relative, or jewellery. Not all the ashes |
| 5 to 100 cu in | Small or child | A child, or a portion when several relatives each want some |
| 200 cu in | Standard adult | The default size sold, suits most adults up to about 180 lb |
| 200 to 300 cu in | Large adult | Adults above roughly 180 lb |
| 300 to 500 cu in | Oversized | Usually ordered rather than stocked, so allow time |
| 400 cu in and up | Companion | Two people in one urn, often a married couple |
Cubic inches against inches, which are not the same thing
Retailers list both, and people confuse them constantly. Capacity is a volume. Dimensions are the outside of the urn. A 200 cubic inch urn is commonly around 7 by 5 by 10 inches, but a taller narrower one and a squatter wider one can hold exactly the same amount.
Where the outside dimensions actually matter is a columbarium niche, because the niche has a fixed opening and the urn has to physically fit through it. Get the niche dimensions from the cemetery in writing before buying, not after. See columbarium niches and cost.
Two things worth knowing before you buy
- You do not have to buy the urn from the funeral home. Federal law under the FTC Funeral Rule requires them to accept an urn you supply from anywhere, without a handling fee. A funeral home urn runs about $295 and the same thing is routinely half that elsewhere.
- Check the opening, not just the capacity. Ashes usually arrive in a sealed plastic bag inside a temporary container. If you intend to transfer the bag whole rather than pour, the urn needs an opening wide enough to take it, and several decorative designs do not.
Common questions
What size urn do I need for an adult?
The standard adult urn holds 200 cubic inches and suits most adults up to about 180 pounds, because the rule is one cubic inch of capacity for each pound of body weight before cremation. Above roughly 180 pounds, move up to a large adult urn of 200 to 300 cubic inches.
How do you calculate urn size?
Take the body weight in pounds before cremation and allow one cubic inch of urn capacity per pound. Add a margin and round up, because ash volume varies and urns are sold in fixed sizes. An urn slightly too large is fine. One slightly too small is not.
What size urn for a 200 pound person?
About 200 cubic inches by the rule, so buy 220 or more rather than exactly 200. A standard adult urn would be a near miss at that weight and a large adult urn is the safer choice.
How many cubic inches is a standard urn?
200 cubic inches. That is the size a funeral home will offer by default and the size most designs are built to.
What size urn do I need for two people?
A companion urn, sized at the two body weights added together plus a margin. Two adults commonly need 400 cubic inches or more. Some companion urns keep the two sets of ashes in separate compartments, which is worth asking about if that matters to the family.
Are urn dimensions the same as capacity?
No, and they are constantly confused. Capacity is volume in cubic inches. Dimensions are the outside measurements. Two urns of the same capacity can be quite different shapes. Dimensions only matter when the urn has to fit a columbarium niche, and then they matter completely.
Keep reading
Cremation urns, materials and rules · What an urn costs · Direct cremation · Cremation cost