CAGR Calculator: Find Your Real Annual Growth Rate Fast

A CAGR calculator converts a starting value, an ending value, and a time period into one smoothed annual growth percentage using the formula (Ending Value / Starting Value)^(1/Years) minus 1, giving you a single number to compare against benchmarks like the S&P 500.

Most people reach for CAGR when they want to compare two investments that grew over different time periods, or when a percentage return by itself does not mean much without knowing how long it took to get there. A 50% return sounds great until you learn it took 12 years, at which point the CAGR of about 3.5% tells a very different story than the headline number. The same math works whether you are looking at a single stock, a whole portfolio, a business's revenue line, or the value of a piece of real estate, since CAGR only cares about the start value, the end value, and how much time passed between them.

This guide walks through the exact formula, shows how CAGR compares to a simple average return with real numbers, and covers where it quietly hides risk that a single percentage can never capture.

What is a good CAGR for a stock portfolio?

A CAGR between 8% and 10% a year is considered solid for a diversified stock portfolio over a decade or more, since it roughly matches the S&P 500's long-run average of about 10.4% annually since 1957 with dividends reinvested. Anything sustained above 15% a year for a long period is rare and usually involves concentrated risk.

Context matters more than the raw number. A 6% CAGR on a bond-heavy portfolio during a low-rate decade can be a strong result, while the same 6% on an all-stock portfolio during a bull market decade would lag the benchmark badly. Always compare your CAGR to a benchmark that matches your actual asset mix and time period, not to the S&P 500 by default.

A diversified stock portfolio tracking the S&P 500 has produced a CAGR near 10.4% annually since 1957 with dividends reinvested, which remains the standard benchmark most CAGR results should be measured against.

How do you calculate CAGR?

The CAGR formula needs exactly three inputs: your starting value, your ending value, and the number of years between them. Once you have those, the math is the same every time, whether you are measuring a stock, a business's revenue, or a whole portfolio.

A $10,000 investment that grows to $20,000 over exactly 5 years produces a CAGR of 14.87%, a figure that stays constant no matter how uneven the year-to-year path was to get there.

How does CAGR change with different time periods?

The same dollar growth produces a very different CAGR depending on how long it took. Doubling your money in 2 years is a dramatically stronger result than doubling it in 20 years, even though the ending multiple, 2x, is identical in both cases. This is the exact reason CAGR exists instead of everyone just quoting total percentage gain.

This table is also a fast sanity check on any investment pitch. If someone promises your money will double in 3 years, they are implicitly promising a 26% annual CAGR, a figure that would rank among the best hedge fund managers in history if sustained. Treat any pitch with an implied CAGR above 20% to 25% a year as high risk by definition, not as an overlooked opportunity.

Doubling an investment in 3 years implies a 26% annual CAGR, a rate high enough that any pitch promising it deserves the same scrutiny you would give a claim of beating the top professional fund managers.

CAGR vs average annual return: what is the difference?

Average annual return simply adds up each year's percentage return and divides by the number of years. CAGR instead finds the single constant rate that would produce the same ending value through compounding. The two numbers are close when returns are steady and diverge sharply when returns are volatile.

In that example, simple average annual return says the portfolio grew by 10% a year, but the account actually lost money. CAGR is the number that matches reality, which is why professional performance reports lean on it instead of a simple average.

What can make a CAGR number misleading?

CAGR by itself cannot distinguish between a smooth, steady climb and a portfolio that crashed 50% before fully recovering, which is why it should always be paired with a look at maximum drawdown, not used alone.

This blind spot is also why two funds can advertise the exact same 10-year CAGR while one made for a comfortable ride and the other tested every investor's patience with multiple 30%-plus drawdowns along the way. Before committing new money based on a marketed CAGR figure, ask for the fund's maximum drawdown and its worst calendar year alongside the headline number.

How do you use a CAGR calculator correctly?

• Use exact dates or exact fractional years, not rounded whole years, for small time periods
• Include dividends reinvested if you are comparing against a total-return benchmark like the S&P 500
• Do not mix in additional contributions or withdrawals without adjusting for them separately
• Compare your CAGR to a benchmark that matches your actual asset allocation and time period
• Pair CAGR with a max drawdown figure so you understand the ride, not just the destination

Running your numbers through this checklist before trusting a CAGR figure takes a few minutes and prevents the two most common errors: comparing against the wrong benchmark and ignoring cash flows that were not part of the original investment.

How do you calculate CAGR when you add money along the way?

The standard CAGR formula assumes a single lump sum invested at the start and left untouched until the end. Most real portfolios do not work that way, since people add contributions every month or year through a 401k or brokerage auto-invest plan. Plugging a portfolio with regular contributions straight into the basic CAGR formula will overstate your actual investment performance.

For portfolios with ongoing contributions, the more accurate figure is the money-weighted rate of return, sometimes called the internal rate of return, which accounts for the timing and size of every deposit. Most brokerage platforms, including Fidelity and Schwab, calculate this automatically and display it separately from a simple CAGR on your account performance page.

A portfolio funded through regular monthly contributions needs a money-weighted return calculation, not a basic CAGR formula, to accurately reflect performance against a lump-sum benchmark like the S&P 500.

The verdict: when should you actually use CAGR?

CAGR is the right tool any time you need to compare growth across different time periods or explain a bumpy multi-year return in one clean number. It is the standard way to describe long-term portfolio performance, business revenue growth, or the annualized return on a real estate holding.

It is the wrong tool when you need to understand risk, volatility, or how painful the path was along the way. In those cases, pair your CAGR figure with a max drawdown percentage and a standard deviation figure so the full picture is visible, not just the smoothed average.

CAGR answers one question well: what constant annual growth rate would have produced this same ending value, and that makes it the right benchmark for comparing investments, not for judging how risky the ride was to get there.