# How to Calculate IRR on an HP-12c Calculator

by Carter McBride; Updated September 26, 2017Businesses use internal rate of return (IRR) to calculate potential return rates for projects and thus compare two or more projects. If you have a Hewlett-Packard (HP) 12c financial calculator, you can calculate IRR using the "IRR" button. To calculate IRR, you must know initial investment, any additional cash flows, the frequencies of any future cash flows and your expected return cash flow.

Type your initial investment into the calculator.

Press "g" and then "CFo" to record the initial cash flow.

Enter your first cash flow. Press "g" and then "CFi" to record your first cash flow.

Repeat Step 3 for each cash flow.

Type the number of times the cash flow occurs, then press "g" followed by "N."

Repeat Steps 4 and 5 for any additional cash flows.

Type your final cash flow amount, followed by "g" and then "CFi."

Type the interest rate as a percentage — not a decimal — and press "i."

Press "f" and then "IRR" to calculate IRR.