Lye Calculator for Making Cold Process Soap

Our lye calculator makes it easy for you to create your own cold process soap recipe. Choose your base oils, superfatting percentage, and liquid, then click on the "Compute Lye" button and let our lye calculator do the rest.

Remember... although the lye calculator can compute how much lye is needed for almost any oil combination, not all oils will make the same quality of soap. The oils you choose will determine your soap's hardness, how well it lathers, and how moisturizing it is. For example, tallow, lard, or palm oil will give hardness to soap. Coconut oil is great for lather... palm kernel has similar characteristics and can be used in recipes instead of coconut oil. Olive oil, vegetable shortening, or castor oil are also good soap making oils, especially when combined with the oils mentioned previously. Finally, don't forget to choose a moisturizing oil like sweet almond, avocado, or jojoba to superfat.

Disclaimer: We have taken every precaution to ensure that the information provided by this lye calculator is accurate. However, because personal techniques and soap making conditions can vary so widely, we cannot guarantee results or be held responsible for soap making failures. Lye is a very caustic substance... handle it with extreme caution and follow all safety guidelines. The SAP values used in this lye calculator were obtained directly from several oil manufacturers. In cases where we were given a range of values for the same oil, we used an average of the values.


Recipe title (required):

Date recipe was created (required):

Name of person who created recipe (required):

Oil #1:
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Oil #2:
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Oil #9:
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Superfatting percentage:

Units (choose measurement type):

Type of lye:

Type of liquid:

Note: 8.5 ounces of milk and 6 ounces of water are the same volume measurement... milk weighs more than water.

A reminder — The usual disclaimers apply. The recipes in this library reflect the individual contributors' own methods of soapmaking and are written in their own words. We cannot personally guarantee the success or results of any of the recipes included in this library.