How to calculate for other ingredients on soap calculators

[Guest]

I want to make the laundry detergent, and wouldn't you know that I have 14.7 oz of lard, not 16 oz. So I wanted to run it through a soap calculator and it says I need quite a bit less lye than the posted recipe says for the original recipe. I am thinking that is because of the added borax and laundry detergent. How do you run those extra ingredients through a soap calculator?

 

[carebear]

the amount of lye can vary a bit from calculator to calculator. this is because the actual SAP value of an oil actually falls within a RAGE and is not always the exact same number. some calculators use a number in the middle of the range, some at one end - all are equally "correct". your superfat/lye discount takes care of that. borax has nothing to do with it.

you add laundry detergent to the detergent??

anyway, no you don't put the extras in the calculator - just oils.