Tying your own leaders – is there a chart somewhere to determine which line poundage to use for each section?

I recently got back into fly fishing after about a 8 year hiatus. I used to tie my own leaders and I feel like there was a chart somewhere I used to determine which line strength to use for each section, but I haven't been able to find it. I used the 60/20/20 rule too I believe. Does anyone have a link to a chart or a general rule of thumb to go by?

For example, I would like to tie up some 6 foot leaders which end in 5 pounds (3X tippet material I believe). What I'd like to know is what to use for the butt and middle sections.

Edit: I found it, linking in case someone else has the same question later.

https://globalflyfisher.com/leadercalc