How is the name rune calculated?

Write your name on a piece of paper. Assign a numerical value to each letter as shown in the table you can find here. Then form the transverse sum of the individual digits of this sum. If the cross sum is greater than 24, repeat the process. You will get a number between 1 and 24. Now you can see here which rune is assigned to which value.

You can find a detailed guide here.