Cremation ashes weigh 4.0 to 5.0 pounds on average for adult females and 6.2 to 7.5 pounds on average for adult males. The average cremation weight across all adults is 5.9 pounds. This is according to a review of four studies published in the Journal of Forensic Sciences in 2011. According to this study, while the ashes of males weighed 1.2 to 3.5 pounds more than females there was significant overlap for weights between the groups.
The original body weight is one way to estimate the weight of ashes. Ashes generally weight between 3.5% and 4.5% of body weight but this can be 2.5% to 6.0% depending on other factors. We have developed a calculator to generate a more realistic estimate and range of ash weight based on starting body weight.
You may be planning what size urn to get, or you may just be curious how much ashes there are after a human cremation. The weight of cremation ashes is typically heavier than people expect. Maybe because the word “ashes” reminds us of the light remains from a wood fire. In reality, ashes that you get after a cremation are more like coarse sand or fine gravel. Cremated remains are really the ground up bones, not the “ashes” that come back after cremation.
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Cremation Ashes Body Weight Calculator
You can use this calculator to get an estimate of how much cremation ashes may weigh depending on body weight. The calculator also provides a high end and low end estimate as there can be a lot of variation in the actual amount of ash, even for bodies of the same weight.
This calculator has been developed by us here at Occasional Sage based on the results from a study by Shannon E. May published in the Journal of Forensic Sciences in 2011. See the image below which the calculator is based on.
Cremation Ashes Compared to Body Weight
The weight of cremated ashes is between 3.5% and 4.5% of body weight on average based on published studies. However there is a large variation and ash weights can commonly be between 2.5% and 6.0% of body weight. The ratio also changes across different body weights. Heavier bodies generally have ashes that are a lower percentage of their body weight compared to lighter bodies.
A widely cited study suggests that for adults the weight of ashes is approximately 3.5% of the body weight. However this is based on only 91 samples from one crematory. A further study in the US with a larger sample suggests the weight of cremated ashes as a percentage of body weight changes depending on the body weight. The ashes from heavier bodies are a lower percentage
Another study in Thailand showed cremated ashes were 4-4.5% of body weight. It is likely that bodies with lots of fat have a lower proportion of ash to body weight. Americans have much higher fat levels on average compared to Thai so it makes sense that Thai levels show a higher percentage.
The most comprehensive study compiled data from four scientific papers measuring the weights of cremation ashes (cremains) compared to body weight (perimortem body mass). The study included a sample of 761 cremations.
What Are Ashes Made From?
Cremation ashes are the pulverized particles of the remains of bones left behind after cremation. Traditional flame cremation incinerates all liquids and organic matter in the body, leaving behind only the inorganic parts of the bones. These parts give the bones their solid structure and are mainly made up of calcium phosphate. There is about a 30%-40% reduction in the weight of the bones once the organic parts have been burned away. The organic parts are mainly collagen from the bone marrow.
Learn more about the steps in the cremation process.
Factors Determining the Weight of Ashes
The weight in ashes comes from the weight of the inorganic bone structure. Bigger and denser bones will weigh more, so anything that affects the size and density of bones will affect the weight of the ashes.
Height
Height is the strongest indicator of the weight of ashes from cremation. Taller people have larger bones so taller people will have heavier ashes.
Body Weight
Weight is the second strongest indicator of the weight of ashes. Body weight is relevant in a few ways:
- Heavier people are taller and wider, so have larger bones.
- Heavier people can have higher bone density because bones become denser to deal with the extra weight.
Sex
Men tend to have heavier ashes than women for a few reasons:
- Men are taller and broader than women on average so their bones are larger.
- Men have denser bones than women, so the ashes are heavier. This is particularly true for women post menopause who lose bone density.
- Men tend to die at younger ages and younger people have denser bones than older people.
Age
Bone density decreases with age so younger people tend to have heavier ashes than old people. Females lose weight at almost twice the rate of males. A 2004 study found that the weight of female ashes tends to decrease by 0.58 ounces (16.55 g) for every year they are older. Male ashes went down by 0.29 ounces (8.19 g) for every year.
Maturity
Children have lower bone density than adults so children’s ashes tend to weigh less than adults, even taking into account height.
Volume of Ashes for Cremation Urn
An often quoted industry rule of thumb is to add one cubic inch for every pound of body weight to get to the urn size you need. So a 200 pound person would need an urn with 200 cubic inches volume. As we have seen, because ash weight and volume can change so much even for people of the same weight this rule may be of limited use.
The industry standard size for an urn is 200 cubic inches and this fits most people’s but not everyone’s ashes. There are a wide variety of urns at 220 cubic inches or more available. If you really want to keep all the ashes together you have a couple options:
- Buy an oversize urn to be extra sure the ashes will fit.
- Wait until the ashes are ready before deciding on an urn.
What to do if Ashes Won’t Fit in the Urn
- Take the excess ashes and scatter them in a special place, perhaps using a second scattering urn.
- Separate the ashes into more than one urn, perhaps leaving one with another family member.
- Cremation jewelry or diamonds are an option but these only use a very small portion of ashes.
- The last option will be to just buy another urn that does fit. This will understandably be annoying especially if you’ve ‘ve already chosen the perfect urn and don’t want to spend more money.
How Much Does a Person Weigh After Cremation?
Body weight before cremation is one way to estimate the weight after cremation although the actual outcomes can vary widely.
How much does a 150 pound person weigh after cremation?
The ashes of a 150 pound person are likely to weigh 5.87 pounds, but it could be up to 8.07 pounds or as low as 3.66 pounds.
How much does a 175 pound person weigh after cremation?
The ashes of a 175 pound person are likely to weigh 6.37 pounds, but it could be up to 8.57 pounds or as low as 4.16 pounds.
How much does a 200 pound person weigh after cremation?
The ashes of a 200 pound person are likely to weigh 6.87 pounds, but it could be up to 9.07 pounds or as low as 4.66 pounds.
How much does a 225 pound person weigh after cremation?
The ashes of a 225 pound person are likely to weigh 7.37 pounds, but it could be up to 9.57 pounds or as low as 5.16 pounds.
How much does a 275 pound person weigh after cremation?
The ashes of a 275 pound person are likely to weigh 8.37 pounds, but it could be up to 10.57 pounds or as low as 6.16 pounds.
How much does a 300 pound person weigh after cremation?
The ashes of a 300 pound person are likely to weigh 8.87 pounds, but it could be up to 11.07 pounds or as low as 6.66 pounds.
Other Questions About Cremation Ashes Weight
What does it mean when ashes are heavy after cremation?
Heavy ashes are very common and are usually because of particularly large or dense bones of the cremated person. Younger, physically active males tend to have denser bones than elderly sedentary females for example, and so will have heavier ashes. Overweight people also have heavier ashes, but it is because they tend to have denser bones.
Do overweight people have heavier ashes?
Yes, overweight people tend to have heavier ashes, but it’s not because of their extra fat – it’s because of their extra bone density.
How to calculate cremation weight in cats and dogs. There is a calculation tool, do you think this is correct, thank you.
That’s an interesting question and I’m not sure of the answer sorry. For the calculators to be comparable cats and dogs would have to have similar body compositions to humans (like how much of them is made from muscle vs fat vs bones). I read that cats have about 17-30% body fat percentage which is not very different to a lot of humans. So the calculators may work for pets too but I wouldn’t be confident.