What is IRR (Internal Rate of Return) in investing?

IRR, the internal rate of return, is the annualised compound return of an investment counting every cash flow over time: the initial investment, ongoing rent income, and the eventual sale price. It's the most complete metric for comparing investments with different holding periods, cash flow patterns and exit values. It is also the one most often misunderstood.

IRR = annualized compound return integrating all cash flows: rent + exit price
Unlike simple ROI, IRR captures timing: the same total return earned sooner gives a much higher IRR
Benchmarks: below 5% weak, 6–9% acceptable, 10%+ excellent for residential real estate
Always compare IRR to your mortgage rate, government bond yield, and index fund returns
The exit price you assume changes everything, so model zero, moderate and high appreciation
Leverage amplifies IRR on equity when asset return > debt cost; magnifies losses when it's reversed

What IRR actually measures

IRR is the discount rate that makes the Net Present Value (NPV) of all cash flows equal to zero. In practical terms: it's the annual compound return you'd need from a bank account to match the investment's total performance over the same period. If IRR is 9%, the investment behaved like money compounding at 9% a year, counting both the rent received year by year and the capital gain at exit.

IRR vs. simple ROI: why timing matters

Simple ROI doesn't account for time: doubling your money in 2 years vs. 10 years both show as 100% ROI. IRR captures the timing. A 100% return in 2 years is an IRR of ~41%; a 100% return in 10 years is only ~7.2% IRR. That makes IRR the right metric for comparing investments of different lengths, which is nearly every real comparison. Two investments with the same total return but different time horizons have very different IRRs.

Step-by-step example

You invest €160,000 (purchase price + acquisition costs). You collect €8,000 in net rent per year for 10 years. At the end of year 10, you sell for €210,000. Cash flows: −€160,000 (year 0), +€8,000/year (years 1–10), +€210,000 (year 10). IRR ≈ 8.5% per year. This means your money compounded at 8.5% annually throughout the investment, combining rental income and capital gain into a single annualized figure.

IRR benchmarks for real estate

For a buy-and-hold residential rental: IRR below 5% is weak (barely beats inflation). 6–9% is acceptable for residential in most European markets. 10%+ is excellent and usually requires buying below market value, a high-appreciation area, or a renovation that increases the property's value significantly. Always compare IRR to: your mortgage interest rate (if IRR > loan cost, the investment creates financial value); the 10-year government bond yield (the risk-free alternative); and the historical return of a global index fund (7–9% nominal annually).

How exit price and hold period change IRR dramatically

The assumed sale price at the end of the holding period has an outsized effect on IRR, especially over longer horizons. A 1-point difference in assumed annual appreciation can shift IRR by 1–2 points. For a 10-year hold, the exit price can represent 40–60% of total return. Always model three scenarios: zero appreciation (rental income only), moderate appreciation (2–3%/year), and strong appreciation (4–5%/year). If IRR is positive only under the optimistic scenario, the investment depends on everything going right.

IRR with leverage: the amplification effect

IRR can be calculated on total investment (price + costs) or on equity only (down payment + costs). When you finance part of the purchase with a mortgage, the IRR on equity is higher than the asset IRR, as long as the debt costs less than the asset returns. This is financial leverage. If the asset IRR is 7% and the mortgage costs 4%, your equity IRR might be 10–12% depending on the loan-to-value ratio. But if the asset IRR drops to 3%, leverage amplifies the loss. Leverage does not create returns. It multiplies whatever the underlying asset produces, positive or negative.

Limitations of IRR and how to address them

IRR has two key limitations. First: it assumes you can reinvest intermediate cash flows (rent) at the same IRR rate, which is often unrealistic. If you can only reinvest rent at 4% but the calculated IRR is 10%, actual performance will be lower. Modified IRR (MIRR) fixes this by using a separate reinvestment rate. Second: IRR can produce multiple values or no solution with irregular or sign-changing cash flows. Use IRR and NPV together: IRR tells you the rate of return; NPV tells you how many euros of value (in today's terms) the investment creates above your benchmark rate.

Frequently asked questions

What is IRR?

The annual return that makes the present value of all cash flows, including the sale, equal to the investment.

Why is IRR better than ROI for long holds?

It accounts for the timing of cash flows, so money received earlier is worth more.

What is a good IRR for real estate?

It depends on risk: lower for stable rentals, higher for renovation or development projects.

What are its limitations?

It assumes reinvestment at the same rate and is very sensitive to the assumed exit price.