Calculate cremated remains from body weight, estimate ashes weight, and check whether an urn has enough capacity to fit the remains.

Cremation Weight Calculator

Use body weight for an ashes estimate, or check whether an urn capacity is large enough.

Body weight
Ashes weight
Urn fit

Cremation Weight Formula

The calculator uses three formulas, one per mode.

Body weight to ashes (estimate):

Ashes (lb) = Body weight (lb) × 0.035

Ashes to body weight (reverse estimate):

Body weight (lb) = Ashes (lb) / 0.035

Urn capacity rule:

Urn capacity (cu in) = Body weight (lb) × 1
  • Body weight – the person’s weight in pounds before cremation
  • Ashes – the weight of the cremated remains
  • 0.035 – the midpoint of the 3–5% conversion range
  • Urn capacity – the interior volume of the urn in cubic inches

The 3.5% figure is an average. Actual remains range from about 3% to 5% of body weight, depending on bone density rather than fat or muscle mass. The 1 cubic inch per pound rule is the industry standard used by urn manufacturers and funeral homes.

Reference Tables

Typical adult cremated remains and matching urn sizes:

Body weight Expected ashes Min urn capacity
100 lb (45 kg)3–5 lb100 cu in
150 lb (68 kg)4.5–7.5 lb150 cu in
200 lb (91 kg)6–10 lb200 cu in
250 lb (113 kg)7.5–12.5 lb250 cu in
300 lb (136 kg)9–15 lb300 cu in

Standard urn sizes by category:

Urn type Capacity Typical use
Keepsake3–50 cu inPartial remains
Infant / child10–100 cu inInfants, small children
Companion (adult)160–220 cu inAverage adult
Standard adult200 cu inUp to 200 lb body weight
Oversize adult250–450 cu inBody weight over 200 lb
Companion (couple)350–500 cu inTwo sets of remains

Example and FAQ

Example: For a 180 lb adult, expect about 6.3 lb of cremated remains (180 × 0.035) and an urn of at least 180 cu in. A standard 200 cu in urn fits with 20 cu in to spare.

Why is body weight used to size urns instead of ashes weight? Cremated remains volume tracks closely with skeletal size, which scales with body weight. The 1 cu in per pound rule produces a reliable result without needing the actual ashes weight.

Does body fat affect the amount of ashes? No. Soft tissue is consumed during cremation. Bone structure determines the final weight and volume, which is why taller and heavier-framed people produce more remains.

Will all remains fit in a standard 200 cu in urn? Usually yes for adults up to about 200 lb. Above that weight, choose an oversize urn or a larger companion size.

How much do cremated remains weigh on average? Most adults produce 4 to 8 lb of remains, with a typical average near 5 to 6 lb.