Internal Rate of Return

IRR is the standard yardstick for measuring performance in private investments — private equity, private credit, real estate funds, and direct investments — where capital is called and returned in irregular chunks over many years rather than sitting in an account earning a visible daily return. Because IRR accounts for both the size and the timing of every cash flow, it rewards investments that return capital quickly and penalizes those that tie up money for a long time before delivering gains.

The mechanics: IRR is the discount rate that makes the net present value (NPV) of all cash flows — outflows when capital is invested, inflows when distributions or proceeds are received — equal to zero. In practice, it is calculated by financial software rather than by hand. A hypothetical illustrative example: a family office commits an illustrative $10 million to a private equity fund, receives distributions over eight years, and ultimately calculates an IRR of a certain percentage based on the exact timing and size of each cash flow.

A common confusion is treating IRR like a simple annual return. Because IRR is sensitive to timing, a fund that returns capital very early can show a high IRR even if total dollars returned are modest — a dynamic sometimes called the "J-curve" effect in early fund years. Families evaluating managers through manager selection or reviewing due diligence materials will encounter IRR alongside other metrics such as MOIC (multiple of invested capital), and using both together gives a more complete picture than either alone.