Calculate the Compound Annual Growth Rate over time
The value at the beginning of the period (Revenue, Users, Portfolio, etc.)
The value at the end of the period
Usually Years, Months, or Days
Compound Growth Rate (CAGR):0.00%
Total Percentage Growth:0.00%
Absolute Difference:0
Equivalent Excel Formula:
=(End/Start)^(1/n) – 1
How to Calculate Growth Rate Over Time in Excel
Calculating the growth rate over a specific period of time is a fundamental task in financial analysis, biology, and business reporting. While the calculator above gives you instant results, understanding how to perform this calculation in Microsoft Excel is essential for handling large datasets.
1. The Compound Annual Growth Rate (CAGR) Formula
The most accurate way to measure growth over multiple periods (like years) is using the CAGR formula. This assumes the investment or value grew at a steady rate, compounded over time.
The mathematical logic is:
CAGR = (Ending Value / Beginning Value)(1 / Number of Periods) – 1
2. Using Standard Excel Operators
If you do not want to use specific functions, you can type the formula manually into any Excel cell. Assuming:
Cell A1 contains the Starting Value (e.g., 100)
Cell B1 contains the Ending Value (e.g., 200)
Cell C1 contains the Number of Years (e.g., 5)
Your formula would be:
=(B1/A1)^(1/C1)-1
Note: Make sure to format the result cell as a "Percentage" to see the rate correctly.
3. Using the RRI Function in Excel
Excel 2013 and later versions introduced the RRI function, which is specifically designed to calculate the equivalent interest rate (or growth rate) for an investment.
Syntax:=RRI(nper, pv, fv)
nper: The number of periods (Time).
pv: Present Value (Start Value).
fv: Future Value (End Value).
=RRI(5, 100, 200)
4. Calculating Simple Percentage Growth (Period over Period)
If you are looking for the total growth percentage regardless of the time taken (Total Return), the formula is simpler:
=(Ending Value – Beginning Value) / Beginning Value
Use Cases for Growth Rate Calculations
Revenue Growth: Analyzing how much a company's sales have increased over a 5-year strategy.
Portfolio Performance: Determining the annual return on investment (ROI).
User Base: Calculating the viral coefficient or monthly growth of a SaaS platform.
Inflation Adjustment: Determining the rate at which costs have risen over a decade.
function calculateGrowthRate() {
// 1. Get Elements
var startInput = document.getElementById("startValue");
var endInput = document.getElementById("endValue");
var periodInput = document.getElementById("timePeriods");
var cagrDisplay = document.getElementById("cagrResult");
var totalDisplay = document.getElementById("totalGrowthResult");
var diffDisplay = document.getElementById("diffResult");
var resultsSection = document.getElementById("resultsDisplay");
var errorDisplay = document.getElementById("errorDisplay");
var excelStartSpan = document.getElementById("excelStart");
var excelEndSpan = document.getElementById("excelEnd");
var excelPeriodSpan = document.getElementById("excelPeriod");
// 2. Parse Values
var startVal = parseFloat(startInput.value);
var endVal = parseFloat(endInput.value);
var periods = parseFloat(periodInput.value);
// 3. Reset Error State
errorDisplay.style.display = "none";
errorDisplay.innerText = "";
resultsSection.style.display = "none";
// 4. Validation Logic
if (isNaN(startVal) || isNaN(endVal) || isNaN(periods)) {
errorDisplay.innerText = "Please enter valid numeric values for all fields.";
errorDisplay.style.display = "block";
return;
}
if (startVal === 0) {
errorDisplay.innerText = "Starting Value cannot be zero for growth rate calculations (division by zero).";
errorDisplay.style.display = "block";
return;
}
if (periods <= 0) {
errorDisplay.innerText = "Time period must be greater than zero.";
errorDisplay.style.display = "block";
return;
}
if (startVal 0) {
// Calculating geometric growth crossing from negative to positive is mathematically complex and usually undefined in standard CAGR context
// However, we will allow it but warn, or standard CAGR might result in NaN for fractional exponents of negatives.
// Standard CAGR formula breaks if StartVal is negative and exponent is fractional (e.g. roots of negative numbers).
// For web safety, we flag this specific mathematical limitation.
if (periods % 1 !== 0 || periods % 2 === 0) {
// Even roots of negative numbers are imaginary.
errorDisplay.innerText = "Mathematical Error: Cannot calculate standard CAGR with negative start value over this duration.";
errorDisplay.style.display = "block";
return;
}
}
// 5. Calculation Logic
// CAGR Formula: (End / Start)^(1/n) – 1
// Handle negative base with fractional exponent issues in JS by checking sign
var ratio = endVal / startVal;
var cagr = 0;
// Safety check for complex numbers (Negative base to fractional power)
if (ratio < 0) {
errorDisplay.innerText = "Result implies a complex number (negative growth ratio). Please check input signs.";
errorDisplay.style.display = "block";
return;
} else {
cagr = (Math.pow(ratio, (1 / periods)) – 1);
}
var cagrPercent = cagr * 100;
// Total Growth Formula: (End – Start) / Start
var totalGrowth = ((endVal – startVal) / startVal) * 100;
// Absolute Difference
var diff = endVal – startVal;
// 6. Update Display
cagrDisplay.innerText = cagrPercent.toFixed(2) + "%";
totalDisplay.innerText = totalGrowth.toFixed(2) + "%";
diffDisplay.innerText = diff.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Update Excel syntax helpers
excelStartSpan.innerText = startVal;
excelEndSpan.innerText = endVal;
excelPeriodSpan.innerText = periods;
resultsSection.style.display = "block";
}