NPV, XNPV, IRR, and XIRR

Why this lesson matters: NPV, XNPV, IRR, and XIRR

Evaluate investments using dated cash flows and discount rates. In this module, the skill supports a larger goal: Turn assumptions into forecasts, scenarios, investment decisions, and capacity plans. The practical application is to compare an expansion project with its required return.

=XNPV(DiscountRate,CashFlows,Dates)

Build it step by step

Work from the business question toward the formula or tool. Keep the source data separate from the output and make every important assumption visible to the reviewer.

• Separate assumptions, calculations, and outputs.
• Build a base case before adding scenarios.
• Reconcile movements and test sensitivities around the decision threshold.

Check the result and common failure points

A model should balance, expose its assumptions, and respond predictably when key drivers change. Also test a known record, a missing or blank value, and a boundary case. Confirm that ranges are the same size, units are consistent, and copied references move only where intended.

• Compare at least one result with a manual calculation or filtered source record.
• Test blanks, zeros, duplicates, errors, and the exact rule boundary.
• Reconcile row counts or totals before relying on the output.

Use the result in a decision

Compare an expansion project with its required return. Label the output clearly, state its period and unit, and explain the action it supports. A technically correct result is only complete when another person can understand, refresh, and review it.