I am trying to make a 40% lactic acid peel with 90% pure lactic acid. What are the steps needed to dilute the lactic acid to a 40%. I was thinking 1sp of distilled water and 1sp of lactic acid? Please correct me if I am wrong.

Also I am trying to make a 12% lactic acid lotion with 12oz of lotion. Again what are the steps needed to dilute my 90%lactic acid to a 12% to add to my 12oz lotion.

Why don't you just buy a glycolic peel. Or, and this is purely natural, papaya pulp in the blender is an excellent peel

That is if you are looking for a facial peel.

So... what exactly are you looking for?

I want to use lactic acid as the peel because I was told there is no down time with this and your face won't acutally visibly peel the next day.
I am not sure if that is the same for papaya pulp.

I am also trying to make a lactic acid lotion to leave on my skin.