Dog Urn Size Guide

Cremation type affects ash volume. Flame cremation (traditional) typically yields ashes roughly equal to 1 cu in per pound of body weight. Water cremation (alkaline hydrolysis, a.k.a. aquamation) usually produces about 10–20% more ash because the bones are not reduced by fire. In practice, urn size formulas adjust for this: use 1.2 cu in per lb for aquamation (a 20% increase) . For example, a 50 lb dog would need ~50 cu in with flame cremation, but about 60 cu in if water cremated.

Always add extra capacity for aquamation. Experts recommend selecting an urn 10–20% larger than the calculated need for flame cremation. This accounts for the higher ash volume. (Cremation Solutions notes a 50 lb pet should use a ≥60 cu in urn, exactly 10 cu in more than the weight.) In summary:

• Flame cremation: ~1 cu in per lb (≈16–17 ml) .

• Aquamation: ~1.1–1.2 cu in per lb (add 10–20%)

1. Determine your dog’s pre-cremation weight (lbs).
2. Multiply by 1 cu in (flame) or 1.2 cu in (aquamation) to get the minimum volume . For example, 15 lb × 1 = 15 cu in for flame, or 15 lb × 1.2 = 18 cu in for water cremation.
3. Convert to milliliters: 1 cu in ≈ 16.4–17 ml . (So 50 cu in ≈ 820–850 ml.)
4. Add a safety buffer: increase the volume by about 10–15% (10–20% for aquamation) to ensure no overflow. It’s always okay if the urn is slightly larger than needed. Reserve extra space for keepsakes (fur, a collar tag, etc.) if desired.

Following these steps will honor your pet’s memory with a properly sized urn. As one urn guide puts it, “Don’t worry about buying an urn that’s a little too large.”

Q: How big should a dog urn be?

A: As a rule of thumb, choose at least 1 cubic inch per pound of your dog’s weight, plus extra. For example, a 30 lb dog would need a minimum of 30 cu in. It’s safer to add ~10–15 cu in more . Many pet memorial experts emphasize rounding up: e.g., “if your dog weighed 20 lb, shop for urns with 30 cu in capacity or more.” . So size your urn slightly larger than the bare minimum to ensure all ashes fit comfortably.

Q: What size urn do I need for a 50 lb dog?

A: Roughly a 60 cu in urn. Using the 1 cu in/lb rule, 50 lb → 50 cu in. Then add 10–15 cu in extra, giving ~60–65 cu in. This is confirmed by pet urn calculators and suppliers: “If your pet weighs 50 lbs., you will need an urn that is 60 cubic inches or larger.”. In metric, 60 cu in is about 984 ml. If your dog had water cremation, still plan for ~60 cu in (water cremation already accounts for the higher ash volume).

Q: Is there a dog urn capacity chart?

A: Yes. Pet memorial sites often provide tables like the one above. These charts categorize dogs (toy, small, medium, etc.) and list typical urn volumes in cu in and ml. For instance, a mini dog (<10 lb) usually needs ~10 cu in (164 ml), a small dog (10–25 lb) ~35 cu in (574 ml), and so on. Use such charts as a guideline, but always err on the side of extra space.

Q: Should I choose a larger urn for water cremation (aquamation)?

A: Yes. Water cremation yields more ash (about 10–20% more) than flame cremation. Therefore, use roughly 1.1–1.2 cu in per lb for aquamation. In practice, simply pick an urn about 10–20% larger than you would for flame cremation. For example, if a flame cremation requires 50 cu in, plan for 55–60 cu in if your pet was aquamated.

Q: Can I split ashes into multiple urns or keepsakes?

A: Yes. If the calculated urn size seems too large or if family members want keepsakes, you can divide the ashes among multiple smaller urns or keepsake containers. Just ensure each container can hold the portion it’s meant to contain. This is often done for very large dogs or when close family members each want a memorial.