Population Doubling Time
How long a population takes to double at a given growth rate, using the rule of 70 — a rate rather than a forecast.
At 0.85% annual growth the world population doubles in about 82 years, reaching 16.5 billion around 2108 — though actual fertility decline makes that a rate rather than a forecast.
Population Doubling Time
Frequently asked
Is the Population Doubling Time free?
Yes. Every tool on AlphaBetaMinds is free, needs no account and has no usage limit.
Does this tool store what I type?
No. It runs entirely in your browser. Your inputs are never sent to our server, and nothing is logged.
How accurate is it?
It uses the McCrindle generation boundaries (Gen Alpha 2010–2024, Gen Beta 2025–2039) and UN World Population Prospects vital rates. Sources and formulas are on our methodology page.
Can I use the result in an article or report?
Yes, with a credit and a link back to this page. See our terms of use for the full licence.
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