This handy lye calculator will help you figure out how much lye (NaOH or KOH) to add to your soap recipe. Simply choose whether you are making solid or liquid soap, what unit of measure you prefer, enter the amount (by weight) of each oil you are using, and select your superfatting level. Then click "calculate" and you will be shown your complete recipe with options to add notes and print.
For complete instructions and safety tips on making soap we recommend our How to Make CP Soap DVD or the Soapmaker's Companion.
Questions/Suggestions about our Lye Calculator? We'd love to hear from you! Write to us here
The Bramble Berry Lye Calculator assumes a 90% purity for Potassium Hydroxide (liquid soapmaking) and 97% purity for Sodium Hydroxide (solid bar soapmaking). These purity levels are what are commonly available for sale to consumers, including the Lye sold at Bramble Berry.