percentage on fee values

I have a custom field, I want than selecting this field it changes with 2 fee values, the first is asigned to 0 (zero) and the second is asigned to change the total price with an increase of 16%, so i'm trying to make this works, but im unable to do it.

The data on the fee values are:
0
+16%

but this only changes the price, increasing 16 numbers, not the percentage. How can I make this works?

thanks in advance

Hi Suar

Custom Fee Field could not change the total price based on percent. The reason is because total price of the subscription also depends on that custom fee field as well. So instead of adding 16%, you will need to add a fixed amount (for example 50) to have the fee field works

Tuan