Hell of Regeneration
The life span of these sinners in this hell is as follows. Suppose 50 years in the human world is equal to one day in the Four-king Heavens, the first heaven in the realm of desire, where heavenly beings’ life span is 500 years. Suppose 500 years in the Four-king Heavens correspond to one day in the Hell of Regeneration. Sinners in the Hell of Regeneration live as long as 500 years. …
Hell of Black Ropes
One hundred years in the human world correspond to one day in the Heaven of the Thirty-three Gods, the second heaven in the realm of desire, where the life span of heavenly beings is 1,000 years. If 1,000 years in this Thirty-three Heaven are equal to one day in the Hell of Black Ropes, the life span of those sinners who fell into the Hell of Black Ropes is 1,000 years. …
Hell of Crushing
Suppose 200 years in the human world correspond to a day in the Heaven of Yama, the third heaven in the realm of desire, where heavenly beings live for 2,000 years. If 2,000 years in this Heaven of Yama are equal to one day in the Hell of Crushing, the life span of sinners in this hell is 2,000 years. …
Hell of Wailing
Regarding the life span of the sinners in this Hell of Wailing, one day in the human world corresponds to 400 years in the Tuṣita Heaven, the fourth heaven in the realm of desire, where dwellers live as long as 4,000 years. Suppose 4,000 years in this Tuṣita Heaven are equal to one day in the Hell of Wailing, sinners in this hell have to suffer as long as 4,000 years. …
Hell of Great Wailing
Suppose 800 years in the human world equals to one day in the Creating Enjoyment Heaven, the fifth heaven in the realm of desire, where inhabitants live for 8,000 years. Suppose one day in this hell corresponds to 8,000 years in the Creating Enjoyment Heaven, those sinners who fall to the Hell of Great Wailing have to suffer for as long as 8,000 years. …
Hell of Burning Heat
Suppose 1,600 years in the human world correspond to one day and night in the Paranirmitavaśavartin Heaven, the sixth heaven in the realm of desire, where the life span of heavenly beings is 1,600 years. Suppose 1,600 years in the Paranirmitavaśavartin Heaven are equal to one day and night in the Hell of Burning Heat, the sinners in this hell live as long as 1,600 years. …
Hell of Great Burning Heat
The Hell of Great Burning Heat, the seventh of the eight major hells, is located beneath the Hell of Burning Heat, and its length and breadth are the same as the Hell of Burning Heat. However, the torment in this hell is ten times more severe than all the torments of the six hells mentioned above combined. The life span of sinners in this hell is half the length of a medium kalpa. …
Hell of Incessant Suffering (Avīci Hell)
The life span of sinners in this hell is one medium kalpa. Suppose the length of time equivalent to the period during which a man’s life span decreases by one in 100 years from infinite to ten years, and then increases from 10 to 80,000 at the same rate. The time required for this decrease and increase is called a small kalpa, twenty of which constitute a medium kalpa. Those who fall into this Hell of Incessant Suffering are subjected to the great torment of this worst hell for this long period of time.
Ken Hōbō-shō, A Clarification of Slandering the True Dharma, Writings of Nichiren Shōnin, Doctrine 3, Pages 98-103