Because it takes 2 to 4 hours to cremate one body at temperatures between 1,400 and 2,100 degrees Fahrenheit (760 and 1,150 degrees Celsius), the total energy needed is approximately equivalent to the amount of fuel required to travel 4,800 miles (7,725 kilometers). Also:
Before any combustion will occur, a 68 kg body containing 65 percent water would require 100 MJ of thermal energy.
The standard cremation in a modern crematorium uses 28 gallons of fuel.
The average body takes 2 to 3 hours to burn fully, resulting in 3 to 9 pounds (1.4 to 4.1 kilograms) of ash.