The conversion into numbers of generations uses data on the year of birth and death across 51 generations traced through parent-child relationships from Aiko, Princess Toshi all the way to Emperor Jomei of the Japanese imperial family.
Calculations for generations stretching beyond the year 1429 use the average value of these 51 generations.

Reference:Family tree of Japanese monarchs

Author:@tea_eat_ate

Last updated: 2021-09-23