Urn Size Calculator
Enter the weight of the person or pet in pounds or kilograms and choose a single, companion or keepsake urn. The calculator gives the capacity needed, a standard urn size and the volume in litres.
- One cubic inch per pound
- Companion and keepsake
- Litres too
Use healthy adult weight rather than weight at the end of life. For a companion urn, enter both weights added together.
Urns are sized in cubic inches. Funeral directors use a simple rule: one cubic inch of space for each pound of healthy body weight. A 180 lb adult needs an urn of at least 180 cubic inches, so a standard 200 cubic inch urn.
Urn size chart
Single adult urn. Search for a weight.
| Weight (lb) | Weight (kg) | Needs (cu in) | Standard urn |
|---|---|---|---|
| 100 | 45 | 100 | 100 cu in |
| 150 | 68 | 150 | 150 cu in |
| 180 | 82 | 180 | 200 cu in |
| 200 | 91 | 200 | 200 cu in |
| 220 | 100 | 220 | 220 cu in |
| 250 | 113 | 250 | 250 cu in |
| 300 | 136 | 300 | 300 cu in |
Standard adult urns are 200 to 220 cubic inches. Large urns are 250 to 300.
Weight and urn size
Single urn. Slide the weight.
The urn grows in height and width together, so a doubling in capacity makes it only about a quarter taller.
How to choose an urn size
Pounds to cubic inches. Step through it.
Find the weight
Healthy weight.
For pets the same rule works: a 60 lb dog needs a 60 cubic inch urn.
Single, companion or keepsake
Urn types. Compare them.
Holds all of one person's ashes.
Holds two people.
Holds a small share.
Families often choose one main urn and a few keepsakes so ashes can be shared.
Before ordering
Urn checks. Tick each item.
Tick each item as you go.
Check the inside size of the niche or vault before choosing an urn's outside size.
What you get
Urn sizing. Each tile explains one result.
Cubic inches needed.
Next size up.
Metric volume.
lb and kg.
Single to keepsake.
Ashes weigh about 3.5% of body weight, around 6 lb for an adult.
Frequently Asked Questions
No question matches that search.
What size urn do I need?
One cubic inch for each pound of body weight. 180 lb needs at least 180 cubic inches.
What is a standard adult urn size?
200 to 220 cubic inches.
How big is a companion urn?
About 400 cubic inches, enough for two adults.
What size urn for a dog?
One cubic inch per pound. A 50 lb dog needs 50 cubic inches.
How much do ashes weigh?
About 3.5% of body weight, roughly 4 to 8 lb for an adult.
How many litres is an adult urn?
About 3.3 litres for 200 cubic inches.
What if the urn is too small?
Use a keepsake for the rest, or choose the next size up.
An urn with the right space
Use the weight to find the capacity, then round up to a standard size. It is one less thing to worry about at a difficult time.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.