What Size Urn Do I Need?
Updated November 2, 2026
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For most adults, an urn that holds about 200 cubic inches is enough. The usual rule of thumb is one cubic inch of space for every pound the person weighed before cremation, rounded up. Standard adult urns are typically made in the 175 to 300 cubic inch range, so when in doubt, go a size up.
You don't have to buy an urn right away
If you haven't picked an urn yet, the crematory returns the ashes in a temporary container, usually made of cardboard or plastic. There's no deadline to move them. Many families wait until after the service, when they've decided whether to keep, share, bury or scatter the ashes, because that choice decides what kind of urn makes sense.
How to work out the size
- Start with their weight. Someone who weighed 150 pounds needs an urn of at least 150 cubic inches. Someone who weighed 220 pounds needs at least 220.
- Round up, not down. A little extra space is fine. An urn that's too small means some of the ashes won't fit.
- Look for the capacity, not the height. Urns are sold by volume in cubic inches. Two urns that look the same size in a photo can hold very different amounts.
For a sense of scale, the Cremation Association of North America says adult cremated remains usually weigh between four and six pounds.
If the family wants to share the ashes
Keepsake urns are small urns that hold just a portion of the ashes, often somewhere around 3 to 25 cubic inches. They let several family members each keep some at home while the rest goes into a main urn or is buried or scattered.
Companion urns are made for two people, often a couple, and usually start around 400 cubic inches. In Wisconsin, putting more than one person's remains in the same container needs written consent, so ask the funeral home or crematory what paperwork they'll want.
Match the urn to the plan
- Keeping them at home: any material works. Choose something you'll be glad to see every day.
- Burial in a cemetery: ask the cemetery what it requires before you buy, since some have rules about the container.
- Scattering: a scattering urn or tube with an opening made for pouring is much easier to use than a sealed decorative urn.
- Water burial: use a biodegradable urn made for water. Federal rules for burial at sea require it to happen at least three nautical miles from land, with no plastic in the container, and the person who did it must report it to the EPA within 30 days. Lakes and rivers fall under state and local rules, so check before you go.
Wisconsin law lets cremated remains be placed in a grave, niche or crypt, or handled in any other lawful way.
Flying or mailing the ashes
On a plane: TSA allows cremated remains in a carry-on bag, but the container has to show up clearly on the X-ray. It suggests a lighter material such as wood or plastic, and its officers will not open the container, even if you ask. Some airlines don't allow ashes in checked bags, so check with your airline first. The temporary container from the crematory often works well for travel.
By mail: within the US, the Postal Service only takes cremated remains by Priority Mail Express. The ashes need to be in a sealed, sift-proof inner container with cushioning, and the box needs the Postal Service's orange cremated remains label (Label 139). The Post Office has a free box made for this.
You can buy the urn anywhere
You don't have to buy the urn from the funeral home. The Federal Trade Commission says you can bring your own urn, and that a funeral home can't refuse to handle one you bought elsewhere or charge you a fee to use it. Prices online are often lower than in a funeral home's catalog.
Frequently asked questions
What happens if the urn is too small?
Some of the ashes won't fit. You could put the rest in a keepsake urn or scatter them, but it's easier to choose the right size the first time. If you're unsure, ask the funeral home or crematory how much space the ashes take up before you buy.
Can I keep ashes at home in Wisconsin?
Many families do. Wisconsin's cremation law doesn't address keeping ashes at home. If you have other plans for them, such as burial or scattering, check the rules for that place.
How long does the crematory keep the ashes if we haven't decided?
Ask your crematory. In Wisconsin, if the family doesn't decide what to do with the remains, the law lets the crematory return them no sooner than 30 days after the cremation.
This article is general information, not legal advice. Rules for airlines, mail, cemeteries and waterways vary and can change, so check with the people involved before you act. Last checked November 2, 2026.
Sources: Funeralwise: How to choose the right size cremation urn; Cremation Association of North America: The cremation process; FTC: The FTC Funeral Rule; TSA: What can I bring?; USPS Publication 139: How to package and ship cremated remains; EPA: Burial at sea; Wis. Stat. § 440.80.