Annual growth rate is the percentage change in a value, such as revenue, population, or an investment, over a one-year period. It tells you how fast something is growing (or shrinking) from one year to the next, and it’s one of the most common metrics in business, economics, and personal finance. There are two main versions: a simple annual growth rate that divides total change evenly across years, and a compound annual growth rate (CAGR) that accounts for the snowball effect of growth building on itself.
The Basic Formula
The simplest way to calculate annual growth rate is to find the percentage change between two values:
Growth Rate = (New Value − Old Value) ÷ Old Value × 100
If a company earned $500,000 last year and $600,000 this year, the annual growth rate is ($600,000 − $500,000) ÷ $500,000 × 100 = 20%. When you have data spanning multiple years, you can divide that total percentage change by the number of years to get a simple average annual growth rate. If a city’s population went from 100,000 to 150,000 over 10 years, the total growth is 50%, and the simple average annual rate is 5% per year.
This approach is easy to calculate and useful for quick comparisons, but it has a significant blind spot: it ignores compounding. Growth in real life builds on itself. A city that grows by 5% in year one starts year two with a larger population, so the same 5% rate produces a bigger absolute increase. The simple method treats every year’s growth as if it happened on the original base, which can distort the picture over longer time periods.
Compound Annual Growth Rate (CAGR)
CAGR solves the compounding problem. It answers a specific question: what steady annual growth rate would take you from your starting value to your ending value over a given number of years? The formula is:
CAGR = (Ending Value ÷ Beginning Value)^(1 ÷ Number of Years) − 1
If a $1,000 investment grew to $1,500 over five years, you’d calculate ($1,500 ÷ $1,000)^(1 ÷ 5) − 1 = 0.0845, or about 8.45% per year. That means a consistent 8.45% return, compounded annually, would turn $1,000 into $1,500 in exactly five years.
CAGR is especially useful because it smooths out the year-to-year noise. An investment might jump 20% one year and drop 10% the next. The simple average of those two years is 5%. But if you start with $100, you’d have $120 after year one and $108 after year two, a total gain of only 8% over two years, not 10%. CAGR captures this reality; simple averages overstate it.
Why CAGR and Simple Averages Disagree
The gap between CAGR and simple average return grows wider when yearly results are volatile. In calm, steady growth, they’ll be close. But any time negative years are mixed with positive years, or growth swings dramatically, the simple average will paint a rosier picture than what actually happened to your money or your business.
This is why financial analysts prefer CAGR for long-term comparisons. It reflects actual wealth growth more accurately and lets you make apples-to-apples comparisons across different time horizons. Stock A and Stock B might both double from $50 to $100, but if Stock A takes 10 years and Stock B takes 5, Stock B’s CAGR is significantly higher. Simple percentage gain (100% for both) hides that difference entirely.
How Population Growth Rate Works
Demographers use a slightly different approach. The World Bank calculates annual population growth using an exponential formula: divide the natural logarithm of (ending population ÷ beginning population) by the number of years. This produces the exponential rate of growth between two midyear population estimates.
The logic is the same as CAGR: it captures the compounding effect of each year’s population becoming the base for the next year’s growth. A country with 50 million people growing at 2% per year doesn’t add a flat 1 million people annually. It adds 1 million the first year, then 1.02 million the next, and so on. The exponential formula reflects that acceleration.
Real-World Benchmarks
Knowing the formula is only half the picture. You also need a sense of what “good” or “normal” looks like in different contexts.
- Global GDP: The International Monetary Fund projects global economic growth at about 3.0% for 2025 and 3.1% for 2026. Growth rates in this range are considered moderate for the world economy as a whole.
- Stock market: The S&P 500 has delivered an average annualized return of roughly 10% since 1957 through the end of 2022. That figure includes both booming years and crashes, which is precisely why CAGR is the standard way to report it.
- Startup revenue: Early-stage software companies operate on a different scale. In 2025, the median annual revenue growth rate for B2B startups was 28%, down from 47% in 2024. Top-quartile companies grew at 65%, compared to 88% the prior year. These rates reflect the rapid scaling investors expect from young companies and are far above what mature businesses typically achieve.
Context matters enormously. A 10% annual growth rate is excellent for a large public company, ordinary for a stock index over decades, and potentially disappointing for a venture-backed startup.
How to Calculate It in a Spreadsheet
You don’t need to do the math by hand. In Excel or Google Sheets, CAGR is straightforward:
If your beginning value is in cell A1, your ending value is in A2, and the number of years is in A3, type: =(A2/A1)^(1/A3)-1. Format the result as a percentage.
For more complex scenarios where cash flows happen at irregular intervals, Excel’s XIRR function handles the calculation automatically. You provide a column of values (investments as negatives, returns as positives) and a column of corresponding dates, and the function returns the annualized rate of return. Microsoft’s own documentation recommends XIRR as the go-to function for CAGR calculations when your data includes specific dates rather than just a start and end point.
Choosing the Right Version
Use the simple growth rate when you’re comparing just two consecutive periods, like this quarter versus last quarter or this year versus last year. There’s no compounding to worry about over a single period, so the basic percentage change formula works perfectly.
Switch to CAGR whenever you’re looking at growth across three or more years, comparing investments or companies over different time spans, or trying to project future values based on past performance. CAGR gives you the smoothed, compounded rate that reflects how value actually accumulates over time.
For population data or any metric that changes continuously rather than in discrete annual jumps, the exponential growth rate used by organizations like the World Bank is the most precise option. In practice, though, CAGR and exponential growth rates produce very similar results for moderate growth rates, typically diverging only at high percentages.