CAGR Calculator (Compound Annual Growth Rate)
CAGR, or compound annual growth rate, compresses a beginning value, ending value, and time period into one smoothed annual rate. It answers a different question from a future value calculator. Future value asks what an amount could become at a stated rate. CAGR asks what rate would have been required to move from the starting value to the ending value over the entered number of periods.
This makes CAGR popular for investments, revenue, users, market size, home values, portfolio balances, and other metrics that can grow or shrink over time. The calculator returns the compound annual growth rate, change in value, total growth, growth multiple, and period count. It does not model deposits, withdrawals, volatility, or taxes. For contribution-based growth, use the compound interest calculator. For a one-lump-sum projection, use the future value calculator. For a quick doubling-time intuition, use the Rule of 72 calculator.
What the calculator computes
The form reads initial value, final value, and number of periods. The initial value must be greater than zero, the final value must be zero or greater, and the period count must be greater than zero. The compute function divides final value by initial value to get the growth multiple. It then raises that multiple to the power of one divided by the number of periods and subtracts one. The result is multiplied by 100 for display as a percentage.
The calculator also computes simple total growth, which is the total change divided by the initial value. That number is not annualized. A 45% total gain over seven years is not the same as 45% per year. CAGR translates the same start and end points into the constant annual compound rate that would reproduce the ending value.
Formula
The CAGR formula is:
Total growth is:
The growth multiple is:
where is the number of periods. The form labels periods in years, but the math works for any consistent period. If you enter quarters, the resulting rate is per quarter; if you enter years, the resulting rate is annual.
Worked example matching the calculator
Use the form’s default-style values: initial value of $310,000, final value of $450,000, and 7 periods. First calculate the growth multiple:
Then apply the CAGR formula:
That equals about 0.054682, or 5.47% when displayed as a percentage. The change in value is:
Total growth is:
So the calculator reports compound annual growth rate of 5.47%, change in value of $140,000, total growth of 45.16%, growth multiple of about 1.452×, and 7 years. The CAGR is much smaller than the total growth percentage because it spreads the movement across seven compounding periods.
Why CAGR is useful and limited
CAGR is useful because it makes uneven histories comparable. A business that grows from $1 million to $2 million in five years and an investment that grows from $10,000 to $20,000 in five years both doubled, so their CAGRs match even though the dollar scale differs. The metric focuses on proportional compound growth.
That smoothing is also the main limitation. CAGR hides the path. One portfolio might climb steadily, while another falls sharply and then rebounds. If both start and end at the same values over the same period, their CAGRs are identical. CAGR also ignores interim cash flows. If you added money halfway through, the ending value reflects both investment performance and new contributions, so CAGR may overstate the investment return.
For present-day equivalents of future lump sums, use the present value calculator. For non-compounding rate math, use the simple interest calculator. For recurring equal payments, annuity calculators are more appropriate than CAGR because they account for payment timing.
CAGR can still be a strong first-pass summary when the beginning and ending values are trustworthy. Use it to compare periods of equal length, explain long-term growth in a single rate, or sanity-check whether a forecasted ending value implies a reasonable annual pace. Then add context before making decisions.
Practical tips
- Use the same unit for initial and final values.
- Make sure the period count matches the interpretation you want.
- Do not divide total growth by years and call it CAGR.
- Be cautious when cash flows occurred during the period.
- Pair CAGR with volatility, drawdown, and fee information when evaluating investments.
- Treat the output as informational, not investment advice or a performance guarantee.
Sources
- SEC Investor.gov, Compound Interest — background on compound growth concepts.
- CFPB, What is an interest rate? — consumer context for rates.
- Federal Reserve, Selected Interest Rates H.15 — public reference for rate data used in financial comparisons.