Looking for guidance on cutting new springs for a slight drop

[Onebean]

I'm rebuilding the front suspension on my 72 C10, and planned to reuse the existing coils to get me by till I can buy a drop kit. Unfortunately, I found one of my springs was broken when I pulled it apart. Now I'm thinking I will buy a new set of springs and cut them off a little bit to achieve the current ride height of the worn out springs. Can anyone tell me how much to cut off of a new spring to achieve a specific ride height? Thanks for the help.

Onebean