Pre-flood population calculator

Use the figures entered below to calculate the population after a given period of time.

Enter your own values to test different scenarios. You will find that very minor changes to the variables can make huge changes to the end result.

The calculator works by calculating how many women could bear children each year. It then adds the births and minuses the deaths each year of the given time period. The first year assumes that a mother exists and gives birth to her first child.

How this works

The population for each year is calculated using the formula below and the results of births and total population are stored and used for the following year. This is done until the last year is reached.

population = population
+ ((number of married women (b) within the 'start family' (c) to 'stop family' (d) year range) / No. of years between births (e) )
- number of people that hit the average lifespan (a)
Length of time
(1656 yrs from Adams creation to the flood minus 100 yrs from Adams creation to Cains birth)
Average lifespan (a):
Percentage of people marrying (b):
Average age to start family (woman) (c):
Average age to stop family (woman) (d):
No. of years between births (e):