NPV & IRR Calculator

Calculate net present value, IRR, MIRR, profitability index and payback for a series of periodic cash flows, with an Excel-equivalent formula.

Currency

Discount rate per period (%)

Reinvestment rate for MIRR (%)

Negative cash flows are financed at the discount rate, as in Excel's MIRR(values, finance_rate, reinvest_rate).

Timing of the first cash flow

Cash flows, one per period

Start with the initial investment as a negative number. Use a point for decimals; thousand separators are ignored.

RESULT

Enter a discount rate and cash flows to see NPV and IRR.

USING THIS TOOL

How the NPV & IRR Calculator helps

Net present value tells you what a stream of future cash flows is worth today at your required return; the internal rate of return is the discount rate at which that value is exactly zero. Together they answer whether a project, purchase or investment beats your hurdle rate. This calculator also reports MIRR, the profitability index and simple and discounted payback, and warns you when unusual cash flows produce more than one IRR.

Formulas

NPV = Σ CFₜ ÷ (1 + r)ᵗ, with t starting at 0 for an upfront investment. IRR is the rate that makes NPV = 0, found numerically. MIRR compounds positive flows at the reinvestment rate and discounts negative flows at the finance rate (here the discount rate), matching Excel's MIRR(values, finance_rate, reinvest_rate). Profitability index = present value of future flows ÷ initial investment.

Excel's NPV() trap

Excel's NPV() assumes the first value occurs one period from now. For an investment made today, the correct formula is =B1 + NPV(rate, B2:Bn). The calculator shows the matching formula for whichever timing you choose. For irregular dates, use the XIRR & XNPV calculator.

Example

An investment of 10,000 returning 3,000, 4,200, 6,800 and 2,500 over four years has an NPV of 3,614.23 at an 8% discount rate and an IRR of about 22.8%. It pays back in 2.41 years, or 2.67 years on a discounted basis.

Frequently asked questions

What discount rate should I use?

Use your required rate of return: the cost of capital for a business, or the return you could earn elsewhere at similar risk. The sensitivity table shows how NPV changes at nearby rates.

Why does the calculator show two IRRs?

When cash flows change sign more than once, for example a large cost in the middle of a project, the NPV curve can cross zero more than once. Then IRR is ambiguous and NPV or MIRR is the better decision rule.

Should I use NPV or IRR?

NPV measures value in currency and handles projects of different size and timing correctly. IRR is easy to communicate but can mislead when comparing mutually exclusive projects.

Know the limits

Assumes equal-length periods and end-of-period cash flows after period 0. Taxes, inflation and risk adjustments must be built into the cash flows or rate. Not investment advice.