IRR vs CAGR: A Comprehensive Comparison for Investors

Methodology note: CAGR is valid for one beginning value and one ending value with no intervening external cash flows. IRR solves for a periodic rate from equally spaced cash flows; spreadsheet IRR assumes equal spacing, while XIRR uses actual dates. For accounts with contributions or withdrawals, do not compute a naive CAGR from total contributions and ending value. State the dates, sign convention, and annualization method.

The short answer: CAGR (compound annual growth rate) measures the smoothed yearly growth of a single investment from a starting value to an ending value, while IRR (internal rate of return) measures the annualized return of a series of cash flows, accounting for when every deposit and withdrawal happened. Use CAGR for a lump sum you left alone; use IRR whenever money moved in or out along the way. This page is for investors and finance students deciding which metric fits their situation. Work through the definitions, the comparison table, and the worked numbers below, then practice the calculations on your own portfolio history using the lessons in the Finelo app.

Searches for "irr vs cagr" spike around performance reviews for a reason: the two metrics can give very different answers for the same account, and neither is wrong. They answer different questions.

What is CAGR?

Compound annual growth rate answers one question: at what constant yearly rate would a starting amount have to compound to reach its ending amount over a given number of years? The formula is (ending value ÷ beginning value)^(1 ÷ years) − 1.

If $10,000 grows to $16,105 over five years, CAGR is (16,105 ÷ 10,000)^(1/5) − 1 = 10% per year, even if the actual path was lumpy. CAGR smooths volatility into a single clean rate, which makes it ideal for comparing funds, stocks, or business revenue lines over the same period. What CAGR cannot see is cash flow timing: it assumes one deposit at the start and one measurement at the end. Add or withdraw money mid-stream and CAGR quietly stops describing your experience. It also hides drawdowns entirely, so pair it with a risk measure like volatility when judging an investment.

What is IRR?

Internal rate of return answers a harder question: given every cash flow in and out of an investment, each on its actual date, what single discount rate makes the net present value of all those flows equal zero? That rate is the IRR.

Because it weights each dollar by how long it was actually invested, IRR is the standard tool for private equity, real estate deals, and any account with ongoing contributions. It is also called a money-weighted return for exactly that reason. There is no clean algebraic formula; IRR is found iteratively, which is why analysts lean on spreadsheet functions (IRR for regular intervals, XIRR for dated flows) rather than hand math. IRR has quirks: it assumes interim proceeds are reinvested at the IRR itself, and a project whose flows flip sign more than once can produce multiple mathematically valid IRRs. For most personal portfolios those edge cases are rare, but they matter in deal analysis.

Key differences between IRR and CAGR

When to use CAGR vs IRR

• Comparing two funds or stocks over the same window: CAGR. It strips out timing and shows pure growth, which is the fair comparison.
• Judging your own account with monthly contributions: IRR. Your deposits arrived over time, and IRR credits each dollar only for the months it was actually at work.
• Evaluating a rental property or private deal with irregular flows: IRR, since purchase costs, rents, refinances, and the sale all land on different dates.
• Reporting business growth (revenue, users): CAGR, the convention in filings and pitch decks.
• Checking whether your timing added value: compare both. An IRR below the same asset's CAGR means your contributions were poorly timed; an IRR above it means timing helped.

Worked example: same account, two different answers

You invest $10,000 on January 1 of year one. At the start of year four, you add another $10,000. At the end of year five, the account is worth $27,000.

• CAGR treats it as one lump sum: total contributions were $20,000 and the ending value is $27,000, so a naive CAGR over five years is (27,000 ÷ 20,000)^(1/5) − 1 ≈ 6.2%. That understates reality, because the second $10,000 only worked for two years.
• IRR respects the dates: solving for the rate that discounts −10,000 (year 0), −10,000 (year 3), and +27,000 (year 5) to zero gives an IRR of roughly 9% per year. Each dollar is judged only for the time it was invested.

Same account, same ending balance, a gap of nearly three percentage points. Neither number lies; the CAGR describes a lump sum that never existed, while the IRR describes what your money actually did. Rebuild this example in a spreadsheet with XIRR and your own dates once, and you will never confuse the two again.