What is CAGR and why does it matter?

CAGR (Compound Annual Growth Rate) is the rate at which an investment would have grown if it grew at a steady rate annually. It's the most accurate single number to represent investment performance over multiple years because it accounts for compounding.

What's the difference between arithmetic mean and geometric mean return?

Arithmetic mean simply averages your annual returns (sum divided by years). Geometric mean accounts for compounding and volatility — it's always equal to or lower than the arithmetic mean. For evaluating actual wealth growth, geometric mean (CAGR) is the correct metric.

What is the S&P 500's average return?

The S&P 500 has returned approximately 10% per year on average (arithmetic) or about 10.5% CAGR since 1957. However, returns vary wildly year to year, and inflation-adjusted (real) returns are approximately 6.5-7% CAGR.

How does volatility drag affect returns?

Volatility drag is the gap between arithmetic mean and geometric mean. Higher volatility means larger swings, which create larger gaps between the two. A portfolio that swings wildly between gains and losses will have a much lower CAGR than its arithmetic average suggests.

📈Investing

What Is Your Investment's Real Average Annual Return?

What is your portfolio actually returning?

What This Does

When an investment brochure says it "averaged 12% per year," that number is almost certainly the arithmetic average — a figure that overstates your actual wealth growth. The number that really matters is the Compound Annual Growth Rate (CAGR), also called the geometric mean return. These two numbers can differ dramatically, and the difference tells you the real story of your investment's performance. Here's why: if an investment loses 50% one year and gains 100% the next, the arithmetic average is 25%. But you actually made nothing — you broke even. The CAGR is 0%. The arithmetic average ignores the devastating math of sequence-of-returns risk, while CAGR tells you exactly how much your investment grew per year on a compounded basis. This calculator lets you enter your starting value, ending value, and time period to compute your CAGR — your true annualized return. It also accepts year-by-year returns to compute both the arithmetic mean and the geometric mean, showing you the gap between them (which reflects volatility drag). Finally, it benchmarks your return against S&P 500 historical averages and shows what $10,000 would have grown to under your actual return vs the benchmark. Use it to evaluate any investment: your portfolio, a real estate property, a business, or a specific stock or fund.

When Should You Use This?

→Calculating the true annualized return on an investment between two dates
→Comparing your portfolio's actual CAGR against market benchmarks like the S&P 500
→Understanding the difference between arithmetic and geometric mean returns
→Evaluating a fund or stock's real historical performance from a series of annual returns
→Determining whether an investment's reported average return matches its actual wealth growth

Example Scenario

Priya invested $50,000 in a real estate fund in 2017 and it's now worth $88,000 in 2024 — a 7-year hold. She enters the starting and ending values into the CAGR calculator. Her result: 8.4% CAGR. The S&P 500 returned approximately 13.5% CAGR over the same period. While her real estate investment was solid in absolute terms, the comparison shows she underperformed the index by 5+ percentage points per year — a difference worth considering for future allocations.

Average Return Calculator

CAGR, Geometric vs Arithmetic Mean & Volatility Drag

Enter start/end values or annual return series — results update in real time.

Starting Value ($)

Ending Value ($)

Years Held

About This Calculator

This average return calculator computes CAGR (Compound Annual Growth Rate), arithmetic mean, geometric mean, volatility drag, and total return in real time — either from start and end portfolio values, or from a series of annual percentage returns. Results update instantly as you type — no button click required. Two input modes handle both simple lump-sum investments and detailed year-by-year return histories.

The Growth tab visualises portfolio value as an area chart over the full investment horizon, with a separate annual return bar chart (green/red for up/down years) in returns mode. The Benchmarks tab provides a grouped bar chart comparing your $10,000-equivalent final value against cash savings, U.S. bonds, a 60/40 portfolio, and the S&P 500 historical average — with a dollar-value gap table. The Scenarios tab shows how $100,000 compounds at different return rates over the same period, letting you see the cost of underperformance in dollar terms.

The volatility drag metric (arithmetic mean minus CAGR) is a key concept often overlooked in investment analysis. Because compound returns are multiplicative rather than additive, year-to-year volatility reduces real wealth accumulation even when the arithmetic average stays constant. The calculator quantifies this drag and flags cases where it meaningfully distorts the apparent return. Use the Export Full Report button for a print-ready PDF with all tables and insights.

Results are estimates only and do not constitute financial, tax, or legal advice. Always consult a qualified professional before making financial decisions.