Payback & Time Value of Money3 / 11
NPV and IRR: Rigorous Project Evaluation
Net present value and internal rate of return — what they mean and when to use each.
10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026
Net present value and internal rate of return are the two numbers a finance director actually expects to see on a capital request, and between them they answer the two questions payback cannot: does this project create value, and what return does it earn? Both are built directly on the discounting from the previous lesson. This lesson defines them, works the example that catches a payback-approved loser, and settles when to use which.
In this lesson
- 01Net present value: does it create value?
- 02Internal rate of return: what return does it earn?
- 03Which to use
- 04Sources and further reading