Population growth is one of the most important indicators in fields like geography, economics, biology, and urban planning.
When tracking human populations, animal species, or even bacteria in a lab, knowing how to calculate growth helps you understand trends and plan for the future.
With our Population Growth Calculator, you can figure it out in seconds — no spreadsheet needed!
Table of Contents
🌱 What Is Population Growth?
Population growth refers to the increase (or decrease) in the number of individuals in a population over time. This can be a steady growth, a rapid increase, or even a decline depending on births, deaths, immigration, and emigration.
There are two main ways to calculate it:
- Absolute growth: how much the population has changed
- Growth rate (percentage): how fast it’s growing relative to its size
📊 Basic Population Growth Formula
To calculate the population growth rate, use this formula:
Growth Rate (%) = ((Final Population – Initial Population) / Initial Population) × 100
Where:
- Initial Population = population at the beginning
- Final Population = population at the end
- Growth Rate = percent increase or decrease
You can also calculate population after growth with:
Future Population = Initial Population × (1 + Growth Rate)ⁿ
Where:
- n = number of time periods (like years)
🧮 Example
Let’s say a city had:
- 50,000 people in 2010
- 65,000 people in 2020
Growth Rate = ((65,000 – 50,000) / 50,000) × 100 = 30%
So, the city grew by 30% over 10 years.
💡 Why Use a Calculator?
Doing this by hand is fine, but a calculator:
- ✅ Saves time
- ✅ Avoids mistakes
- ✅ Helps with future projections
- ✅ Handles big numbers and decimals automatically
Our Population Growth Calculator helps you:
- Find the growth rate
- Estimate future population
- Compare changes over time