To use a financial calculator for bond valuation, you need to input the relevant information such as the bond's par value, coupon rate, yield to maturity, and number of years until maturity. First, enter the bond's par value, which is the amount the bond issuer agrees to pay the bondholder at maturity. Next, input the coupon rate, which is the annual interest rate paid on the bond.Then, enter the yield to maturity, which is the rate of return expected on the bond if held until maturity.