XIRR vs CAGR for Irregular Investments: What Investors Should Use

CAGR (Compound Annual Growth Rate) answers: "If my investment grew smoothly from A to B over N years, what would the annual rate be?"

CAGR = (Ending Value / Beginning Value)^(1/years) − 1

XIRR (Extended Internal Rate of Return) answers: "Given all my deposits and withdrawals on specific dates, what annualized rate makes the net present value zero?"

The key difference: CAGR works with two numbers (start and end). XIRR works with an entire list of dated cash flows.

Example: You invest $10,000 in January, add $5,000 in July, and the portfolio is worth $17,000 in December. CAGR using just start/end would give a misleading result because it doesn't know about the July deposit. XIRR correctly accounts for the timing of each cash flow.

CAGR is the right choice when:

1. Single investment, no additions: You invested $50,000 five years ago and it's now worth $73,000. CAGR = (73,000/50,000)^(1/5) − 1 = 7.86%.

1. Comparing fund performance: Mutual fund and ETF returns are reported as CAGR because they measure the fund's growth independent of investor cash flows.

1. Historical benchmarking: "The S&P 500 returned 10.5% CAGR over 30 years" is a meaningful comparison baseline.

1. Simple projections: If you want to project lump-sum growth, CAGR gives you a clean number to compound forward.

CAGR's limitation: it ignores everything between start and end. If you added or withdrew money during the period, CAGR produces an inaccurate personal return.

XIRR is essential for:

1. SIP investments: Monthly contributions mean each installment has a different holding period. XIRR correctly weights the return for each deposit's duration.

1. Real estate: You make a down payment, pay monthly mortgage, receive rent, pay maintenance, and eventually sell. XIRR captures the return across all these irregular cash flows.

1. Retirement accounts: Regular contributions plus employer matches, with potential withdrawals, need XIRR for accurate performance measurement.

1. Business investments: Initial capital, follow-on investments, revenue distributions, and final exit—XIRR handles the full lifecycle.

1. Portfolio with rebalancing: Any time you add money, withdraw, or move funds between accounts, XIRR gives you the true personal return.

In Excel or Google Sheets: =XIRR(cash_flow_values, cash_flow_dates). Use negative numbers for money invested and positive for money received.

Consider this scenario:

• Jan 2020: Invest $10,000
• Jan 2021: Market drops 20%, portfolio = $8,000. You invest another $10,000. Total invested: $20,000, portfolio: $18,000.
• Jan 2022: Market rises 40%, portfolio = $25,200.

CAGR (using total invested vs final): Would need careful handling—simple start/end doesn't work with multiple deposits.

XIRR: Accounts for the fact that your second $10,000 only had one year to grow. It calculates that your personal annualized return is about 12.8%.

Conversely, if you had added money right before a big gain, XIRR would be higher than CAGR because more of your capital benefited from the rally. This difference between "fund return" (CAGR) and "investor return" (XIRR) is called the "behavior gap."

XIRR solves for rate r in this equation:

Σ [Cash_flow_i / (1 + r)^((date_i − date_0) / 365)] = 0

This can't be solved algebraically—it requires numerical methods (Newton-Raphson iteration).

Using Excel/Google Sheets:

1. Column A: cash flows (negative for investments, positive for withdrawals/final value)
2. Column B: corresponding dates
3. Formula: =XIRR(A1:A10, B1:B10)

Example setup:

The final row should be positive (your ending value or proceeds). All investment amounts are negative. XIRR returns the annualized rate that makes the net present value of all flows equal zero.

For quick online calculation, use our ROI + CAGR calculator for lump sums or investment growth calculator for regular contributions.