Calculation. Summary: This is the calculation used for figuring the yield to maturity of bonds and coupons purchased after 1984 as described in example 23. To calculate: 2 multiplied by (($100,000 divided by $60,000) raised to (1 divided by ((74 divided by 181) plus 12)) power minus 1 equals 2 multiplied by (1.04203 minus 1) equals .08406 equals 8.406%.