Lye Calculator

The HSCG Lye Calculator is different than other lye calculators because you can see the expected range of the saponification value (SAP Value) of each oil and the actual SAP Value being used in the calculations. With this information, you can more accurately calculate the amount of lye needed for the oils YOU are using

In addition, the HSCG Lye Calculator gives the option to calculate by amount or percentage, and to calculate the lye necessary for soap using sodium hydroxide, postassium hydroxide or both.

Advanced Functionality

Specify SAP Value: Registered Users may specify a different SAP Value for any oil they are using, and that SAP Value will be used in the calculations. Login or Register to access this functionality.

Step 1    Recipe Details

Enter in the specifications for your recipe. This information is used for your information (name and notes) and for doing the actual calculations for the lye for your soap recipe.


Total Batch Size (in ):  

Step 2    Select Oils

Click an oil to add it to your recipe. Click again to remove it.

Note: The oils listed are the ones for which we have specifications. Additional oils may be added in the next step.

Almond Oil, Sweet

Apricot Kernel Oil

Avocado Oil

Babassu Palm Oil


Blackcurrant Oil

Boabab Seed Oil

Borage Oil

Borage Oil (Dwarf)

Borneo Tallow Nut Oil

Brazil Nut Oil


Cameline Oil

Candlenut (Kukui) Oil

Canola Oil (low erucic)

Cashew Nut Oil

Castor Oil

Cherry Kernel Oil

Cocoa Butter

Coconut Oil

Cod Liver Oil

Coffee Bean Oil (Raw)

Coffee Bean Oil (Roasted)

Cohune Nut Oil

Corn Oil

Cottonseed Oil

Dhupa (Malabar) Fat

Domba (Tamanu) Fat

Emu Oil

Evening Primrose Oil

Filbert (Hazelnut) Oil

Ghee Butter (Buffalo Milk)

Goose Fat

Grape Seed Oil

Grapefruit Seed Oil

Hempseed Oil

Horse Fat

Illipe Butter

JoJoba Oil (golden, unrefined)

Jojoba Oil (lite, refined)

Kanya Tallow

Karanja (Pengam) Oil

Kokum Butter


Linseed (Flaxseed) Oil

Linseed Oil (low linolenic)

Mango Butter (Refined)

Mango Seed Oil

Meadowfoam Seed Oil

Mowrah Butter

Neem Oil

Neetsfoot Oil

Niger Seed Oil

Olive Oil

Olive Oil (pomace)

Olive Oil (refined)

Olive Oil (virgin)

Palm Kernel Oil

Palm Oil

Palm Olein

Palm Stearin

Papaya Seed Oil

Peach Kernel Oil

Peanut Oil

Pecan Nut Oil

Perilla Oil

Pine Nut Oil

Pistachio Nut Oil

Plum Kernal Oil

Poppyseed Oil

Pumpkin Seed Oil

Rapeseed Oil (low erucic)

Rapeseed Oil (unhybridized)

Rice Bran Oil

Safflower Oil (high linoleic)

Safflower Oil (high oleic)

Sal (Shorea) Fat

Sesame Seed Oil

Sheanut Butter

Soybean Oil

Sunflower Seed Oil

Sunflower Seed Oil (high oleic)

Sunflower Seed Oil (mid-oleic)

Tall Oil

Tallow (beef)

Teaseed Oil

Walnut Oil

Wheat Germ Oil

Step 3    Oil Amounts

Enter the quantities for each of the oils you selected.

The SAP value range for each oil is shown. The default SAP value used in the calculations is the average for the SAP value range.

Oil / Sap Range SAP Value

Step 4    Additional Oils

If you have any additional oils or ingredients which have SAP values and should be included in calculating the amount of lye, add them here.
Note: Other ingredients or additives for your recipe should be added in Part 5 (below).

Oil Name SAP Value
Add a new line

Step 5    Additives

If you have any more ingredients or additives to include in your recipe, add them here.
Note: Ingredients added here are not included in the lye calculations. Any oils that have saponification values should be added in Part 3 or 4 (above).

Ingredient / Additive Name Amount
Add a new line

Step 6    Options

Select the options for how your results will display.

Step 7   

Disclaimer: The Handcrafted Soap & Cosmetic Guild is providing this lye calculator to soapmakers free of charge. Every effort has been made to ensure that the SAP values used herein are accurate. However, even in the best case, the SAP values provided by reputable sources are only acceptable ranges for each oil. The actual SAP value being used in the calculations is the average of the highest and the lowest acceptable level for an oil and is generally considered the norm for calculating the lye necessary for soap. However, the actual SAP value of any batch of a particular oil may be somewhat higher or lower than the value used in the calculations here (even if it falls within the acceptable range). That all being said, the HSCG is not responsible for any injuries, losses or other damages that may result from using the information provided herein.