NPV & IRR Calculator

Net present value and internal rate of return for a stream of cash flows

About this calculator

The NPV & IRR Calculator evaluates an investment from its stream of period cash flows, with period 0 as the initial outlay. It computes the net present value at your discount rate, solves the internal rate of return by bisection (reporting whether it converged), and finds the payback period with linear interpolation within the recovery year. Discounted and cumulative cash-flow vectors are returned for charting. Cash flows without a sign change have no IRR and are flagged.

How to use the NPV & IRR Calculator calculator

  1. Enter your amounts, rates and terms into the input fields.
  2. Read the result — it updates instantly as you type.
  3. Adjust the inputs to compare scenarios side by side.
  4. Copy the page URL to share the exact calculation.

Common examples

  • −10,000 then 3k, 4k, 5k, 2k at 10% → NPV +1,155.66, IRR 15.32%, payback 2.6 periods
  • −50,000 then 15k, 18k, 21k, 24k at 8% → NPV +13,632.18, IRR 18.76%, payback 2.81
  • −2,000 then 4 × 500 at 12% → NPV −481.33 (reject at 12%), IRR ≈0%, payback exactly 4 periods

Frequently asked questions

How does the NPV & IRR Calculator calculator work?

Enter your amounts, rates and terms, and the calculator applies the standard financial formulas to show the outcome, including intermediate figures where they help you understand the result. All arithmetic runs at high precision, so rounding errors do not build up across periods.

When would I use the NPV & IRR Calculator calculator?

Use it when planning a purchase, loan, investment or budget, to compare options before committing, or to sanity-check figures quoted to you. It is an educational tool, not financial advice — confirm important decisions with your provider or a professional.

How accurate are the results?

The formulas are the standard ones used in finance and run at 30 significant digits internally. Real products may differ in fees, compounding conventions and rounding rules, so treat the result as a close estimate rather than a contractual figure.

Can I share a specific calculation with someone else?

Yes. Every value you enter updates the URL, so copying the address bar and sharing the link reopens the exact same calculation for whoever clicks it.