Enter a Starting Population size (digits only, no commas) for a given Starting Year. Growth Rate is a percentage expressed as a fraction (i.e. 1% growth is 0.01, 10% is 0.1, etc.) If Show Sub-Totals is checked, then the population size for every year up to Ending Year will be displayed.

This calculator attempts to show the power of human numbers to grow exponentially, like the proverbial penny in a savings account that yields millions in interest after a thousand years. Culture, infant mortality, quality of health care, life expectancy, availability of birth control, illiteracy, education, war and pestilence all effect growth, but for the sake of simplicity this calculator assumes consistent growth. In 2000, the world Growth Rate slowed to 1.2% (0.012) but the weight of our own numbers is a clear and present danger.

A few milestones in world population:

1600's - 500,000,000

1800's - 1,000,000,000

1930's - 2,000,000,000

1970's - 4,000,000,000

2000 - 6,000,000,000