How to Calculate Growth Rate Calculator

Leave as 1 if you only want the simple percentage change.

Results

Total Percentage Growth:

Average Annual Growth (CAGR):

Absolute Change:

function calculateGrowthRate() { var start = parseFloat(document.getElementById('startingValue').value); var end = parseFloat(document.getElementById('endingValue').value); var periods = parseFloat(document.getElementById('timePeriods').value); var resultArea = document.getElementById('resultArea'); if (isNaN(start) || isNaN(end) || start === 0) { alert("Please enter valid numbers. Starting value cannot be zero."); return; } // Simple Growth Rate Calculation var simpleGrowth = ((end – start) / Math.abs(start)) * 100; var absoluteChange = end – start; // CAGR Calculation // Formula: [(Ending Value / Starting Value)^(1 / Number of Periods) – 1] * 100 var cagr = 0; if (periods > 0 && (end / start) > 0) { cagr = (Math.pow((end / start), (1 / periods)) – 1) * 100; } else if (periods 0 ? cagr.toFixed(2) + "%" : "N/A (Time period required)"; document.getElementById('absoluteChangeText').innerText = absoluteChange.toLocaleString(); resultArea.style.display = "block"; }

Understanding Growth Rate Calculations

Growth rate is a mathematical concept used to measure the change in a specific variable over a specific period of time, expressed as a percentage. Whether you are tracking population growth, business revenue, website traffic, or biological cell division, the fundamental logic remains consistent.

The Simple Growth Rate Formula

The most basic way to calculate growth is the straight percentage change formula. This is useful for looking at the difference between two points in time without accounting for compounding effects.

Growth Rate = ((Ending Value – Starting Value) / Starting Value) x 100

Compound Annual Growth Rate (CAGR)

When measuring growth over multiple years, the Compound Annual Growth Rate (CAGR) provides a more accurate picture. Unlike simple growth, CAGR assumes that growth compounds—meaning the growth from the first year is added to the base for the second year's growth.

CAGR Formula: [(Ending Value / Starting Value)^(1 / Number of Years) - 1] x 100

Practical Examples

Scenario	Start Value	End Value	Result
Website Traffic (Monthly)	5,000 users	8,500 users	70.00% Growth
Business Revenue (5 Years)	100,000	250,000	20.11% CAGR
Population Increase	1,200,000	1,250,000	4.17% Growth

How to Use This Calculator

1. Starting Value: Enter the number you are starting with (initial population, beginning revenue, etc.).
2. Ending Value: Enter the final number reached at the end of the period.
3. Number of Periods: Enter the duration (days, months, or years). This is required to calculate the annualized growth rate (CAGR).
4. Read the Output: The calculator will provide the total percentage change and the average growth per period.

Why is Growth Rate Important?

Understanding growth rates helps in forecasting and decision-making. If a company knows its revenue is growing at a CAGR of 15%, it can accurately predict its size in three years and hire staff accordingly. In science, growth rates help researchers understand how quickly a virus is spreading or how fast a forest is regenerating.