The internal rate of return is the discount rate at which the NPV profile graph crosses the:

1. An NPV profile graphs net present value against a range of discount rates. 2. Where that line meets zero, net present value is exactly zero. 3. The IRR is the rate at which the NPV profile graph crosses the horizontal axis. 4. So the crossing point on the horizontal axis is the internal rate of return. _Source: OpenStax Principles of Finance (CC BY 4.0), Ch 16 'How Companies Think about Investing', sections 16.1-16.5_