Some people wonder: How heavy are human ashes? To answer that here are some answers based on the age and gender of the deceased person.
Ashes following cremation for a human adult will weigh between 4 to 6 pounds (2 to 3 kg) or around 3.5% of the deceased person’s original weight.
A man's ashes will weight in the 4 lb to 9 lb (1.8 to 4 kg) range.
In the case of children, ashes weigh about 2.5% of the original body weight.
Stillborn infant ashes for a pre-term baby will weigh about 1 to 2 oz. For a full term baby up to 4 oz.
For example:
Fat and muscle do not affect the mass of cremated ashes, which means height and gender (which predict skeletal weight) can be used to accurately predict the weight of the remains.
Note: To choose an urn you you need the volume of ashes (cubic inches or litres) not their weight. You can find volume of human ashes information here.