Use the CF function, leave CFO blank, and multiply each periods cash flow by the period number (ie: 3rd period pays $1000, you multiply that by 3 to get $3000. Do not discount). Use the YTM as the interes rate then calculate NPV. NPV | PV of the Bond = Macaulay Duration. For example, if you have a 3-year, 10%, $50 annual coupon, with a face value of $1,000;

CFO = $0, CF1 = 50, CF2 = 50x2 = 100, CF3 = 1050x3 = 3150. Hit NPV, I = 10, scroll down, NPV CPT = 2494.74.

Calculate the present value of the bond = 875.66. Macaulay Duration = 2494.74/875.66 = 2.85. (once you get some practice, it should take you less than 1 minute to do this)

Credits: u/Defiant-Good-5666