Financial Glossary
Compound Annual Growth Rate (CAGR)
Compound Annual Growth Rate (CAGR) is the mean annual growth rate of an investment, revenue stream, or metric over a multi-year period, assuming the growth compounds each year. It is calculated as: CAGR equals (ending value divided by beginning value) raised to the power of one divided by the number of years, minus one. CAGR smooths out year-to-year volatility and represents the single hypothetical constant rate that would transform the starting value into the ending value over the stated period. It does not reflect actual year-by-year performance, interim volatility, or cash flow timing.
Problem & Application
A campground management platform grows gross booking volume from $2 million in year one to $3.43 million by year three. CAGR equals ($3.43M divided by $2M) raised to the power of one-third, minus one, which equals approximately 19.7 percent. Presenting this CAGR to investors frames growth more cleanly than showing individual year rates of 25 percent, 10 percent, and 25 percent -- which might raise questions about the slow middle year. However, investors scrutinizing the same data will also compute year-over-year rates to identify deceleration signals that CAGR conceals. A fractional CFO presenting financial narratives to growth equity investors should accompany CAGR figures with a bridge showing annual bookings, the drivers of growth in each year, and the assumptions underlying the forward CAGR projection embedded in the model.
In Short
CAGR provides an essential insight into investment growth, particularly for steady assets, making it a valuable metric for assessing and projecting financial goals over time.
How it works
Mathematically, CAGR is a geometric mean, not an arithmetic average: it uses only the beginning value, ending value, and number of compounding periods, expressed as (Ending Value / Beginning Value)^(1/n) − 1, where n is the number of years. In practice, analysts use it to compare investments or business lines with different time horizons on an apples-to-apples annualized basis, and to project forward by reapplying the rate. The most common misunderstanding is treating CAGR as a return you actually earned in any given year; it is a smoothed, hypothetical constant rate, so it understates the impact of volatility and ignores any cash added or withdrawn along the way.
Worked Example: A Short-Term-Rental Portfolio's Revenue CAGR
Suppose an owner-operator runs a small portfolio of vacation rentals. Annual rental revenue was $180,000 at the start of Year 0 and reached $295,000 by the end of Year 4 — a four-year span (n = 4). Applying the formula: CAGR = ($295,000 / $180,000)^(1/4) − 1 = (1.6389)^(0.25) − 1 ≈ 0.1315, or about 13.15% per year. To sanity-check, compounding the start value at that rate reproduces the end value: $180,000 × (1.1315)^4 ≈ $295,000. This single figure lets the operator compare growth against another property bought at a different time, or pitch a lender on annualized trajectory. Note what it hides: if revenue spiked in Year 2 and dipped during an off-season Year 3, the 13.15% reveals none of that volatility. A fractional CFO would pair the CAGR with the actual year-by-year figures before presenting it to a buyer or bank.
Frequently asked
What is the difference between CAGR and average annual growth rate?
CAGR is a geometric mean that accounts for compounding, while average annual growth rate (AAGR) is a simple arithmetic average of each year's percentage change. AAGR overstates growth because it ignores compounding and the order of returns. For example, a +50% year followed by a −50% year gives an AAGR of 0% but a negative CAGR, since you'd end below where you started.
Can CAGR be negative?
Yes. If the ending value is lower than the beginning value, CAGR is negative, representing an average annual decline. For instance, revenue falling from $500,000 to $400,000 over two years produces a CAGR of about −10.6%. CAGR only breaks down mathematically when the beginning value is zero or negative, since the ratio and root become undefined or meaningless in those cases.
How many years should I use to calculate CAGR?
Use the number of full periods between your start and end points — count the intervals, not the data points. Four annual figures span three years (n = 3), not four. There is no required minimum, but very short windows (one to two years) are easily distorted by a single strong or weak year, and CAGR adds the most value over three or more years where it can genuinely smooth volatility.