Internal Rate of Return (IRR)

The internal rate of return (IRR) is the annualised return that accounts for the size and timing of every cash flow into and out of an investment. Technically it is the discount rate that makes the present value of all those cash flows equal to zero; intuitively, it is the single yearly growth rate that would turn the money actually invested, for the time it was actually invested, into the money received back. Because private equity, venture capital, and direct deals draw and return capital irregularly, IRR is the standard performance measure for those investments. It is a money-weighted return: unlike the time-weighted return used for liquid portfolios, it reflects when cash moved, which is exactly what an investor who controls those movements experiences.

Why it matters for family offices

Fund managers report performance as IRR, so families evaluating or comparing private investments need to read it fluently. Its sensitivity to timing cuts both ways. Early distributions lift IRR, and techniques such as subscription credit lines, which delay capital calls, can make a fund's IRR look stronger without changing the cash the family ultimately receives. For that reason experienced allocators typically read IRR alongside cash multiples such as MOIC, DPI, and TVPI: the multiple says how much money came back, the IRR says how fast. Calculating a reliable IRR at the portfolio level also depends on a complete, dated record of every call and distribution, which is a data problem before it is a maths problem.

How it shows up in practice

Suppose a family office invests $1 million in a direct deal today and receives $2 million in a single payment five years later. The IRR is about 14.9% per year, because $1 million compounding at 14.9% annually grows to roughly $2 million over five years. Real fund positions involve dozens of dated flows in both directions, so the rate is solved iteratively by software rather than by hand. The practical work in a family office is upstream of the formula: capturing every capital call, distribution, and fee against the right entity and date, so that the IRR on the quarterly report reflects what actually happened rather than what a spreadsheet remembers.