Apart from the fact that all cinerary ashes must be able to be contained in the funeral urn, no law stipulates that the urn must be 3 liters.
Funeral legislation recommends a minimum capacity of 3 litres to cope with large body sizes of more than 80 kg.
Some crematoriums or funeral providers charge families 3-litre ballot boxes. On average, a 3-litre urn is considered to be significantly sufficient.
Check with your funeral provider before your order to find out the size of the columbarium boxes of the cinerary urn depot. The average dimensions of columbarium cases are 50x50 cm but sometimes less!
To choose the size of a cinerary urn, it is recommended to know the approximate weight of the deceased.
Counting the ballot boxes. Indicative weight of the person. It's not linear and it's not an exact science, it's going to depend a lot on the person's bones.
500 ml -> Up to 10 kg
1 litre -> up to 20 kg
2 litres - > up to 50 kg
3 litres - > - 80 kg (maximum 80 kg)
More than 3 litres -> - 80 kg