Calculator GuideAdvanced Finance Calculators
IRR
IRR explained with examples. Calculate Internal Rate of Return (IRR) for periodic cash flows — evaluate project profitability and compare investment opportunities. Free online IRR calculator. This page walks through the calculation logic, common use cases, and how to read the output.
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When to use it
  • Use it when you need a quick decision-ready view for IRR.
  • Use it when you want to understand the formula and inputs before switching to the interactive tool.
  • Use it when comparing investment, loan, or capital allocation scenarios.
Key inputs
  • Cashflows (comma separated)
Worked example
Evaluate a project or investment with regular-period cash flows and find the discount rate that makes NPV equal zero.

Example inputs

  • Initial investment: -50,000
  • Annual cash flows: 12,000, 15,000, 18,000, 20,000

Formula logic

IRR is the periodic discount rate r where NPV = sum(CFt / (1 + r)^t) equals zero.

How to read the result

Compare IRR with your required return. If IRR only barely clears the hurdle rate, review downside cash-flow assumptions.

Common mistakes
  • Using IRR for irregular dates instead of XIRR.
  • Ignoring multiple-IRR problems when signs change more than once.
  • Assuming all interim cash flows can be reinvested at the IRR.
Common questions
What is IRR best used for?

Calculate Internal Rate of Return (IRR) for periodic cash flows — evaluate project profitability and compare investment opportunities. Free online IRR calculator. This page explains the main inputs and output interpretation before you switch into the full calculator.

When should I use the interactive IRR tool?

Use the interactive tool when you already know your assumptions and want detailed tables, charts, or CSV export.

What inputs does the IRR use?

The formula uses the following inputs: Cashflows (comma separated). Enter them in the calculator above to get precise results.

Is the IRR free to use?

Yes, The Capital Deck's IRR is completely free with no sign-up required.

Can I use the IRR on mobile?

Yes, the calculator works on all modern browsers on desktop and mobile devices.