Saponification Value Calculator
The saponification value (SV) of a fat or oil is the milligrams of potassium hydroxide (KOH) needed to completely saponify one gram of the fat. It is a standard analytical measure in the fats and oils industry used to characterize oils, detect adulteration, and calculate soap-making lye quantities. The theoretical SV from the molecular formula is SV = 3 x 56,110 / MW, because saponification of one triglyceride requires 3 moles of KOH (one per ester linkage) and the MW of KOH is 56.11 g/mol. Enter the average molecular weight of the triglyceride to compute the SV and the equivalent NaOH saponification value.
Saponification value formula
SV (mg KOH/g) = (3 x 56,110) / MW(triglyceride)
NaOH equiv = SV x (40.00 / 56.11)
Three ester bonds per triglyceride each consume one mole of KOH (MW 56.11 g/mol). Multiplying by 1,000 converts g to mg. For NaOH (MW 40.00 g/mol), multiply SV by 40.00/56.11 to get the NaOH saponification value in mg NaOH/g.
Saponification values of common oils
- Coconut oil: 255 to 265 mg KOH/g (short C8-C12 chains).
- Palm kernel oil: 245 to 255 mg KOH/g.
- Olive oil: 185 to 196 mg KOH/g (mainly oleic acid, C18:1).
- Sunflower oil: 188 to 194 mg KOH/g (mostly linoleic acid, C18:2).
- Linseed (flaxseed) oil: 188 to 196 mg KOH/g (highly unsaturated).
Saponification value: frequently asked questions
What is saponification value?
The saponification value (SV) of a fat or oil is the number of milligrams of potassium hydroxide (KOH) required to saponify (completely hydrolyze) one gram of the fat. It reflects the average molecular weight of the fatty acid chains: higher SV means shorter average chain length.
What is the saponification value formula?
SV = (3 x MW of KOH x 1000) / MW of triglyceride = (3 x 56,110) / MW. One triglyceride yields 3 moles of fatty acid soap on saponification, each consuming one mole of KOH (MW 56.11 g/mol). The factor 1000 converts grams to milligrams.
What is a typical saponification value for common fats?
Coconut oil: approximately 255 to 265 mg KOH/g (short-chain fatty acids). Olive oil: approximately 185 to 196 mg KOH/g (mainly oleic acid C18). Lard: approximately 190 to 202 mg KOH/g. Beef tallow: approximately 193 to 202 mg KOH/g.
How is saponification value measured experimentally?
AOCS method Cd 3-25 and ASTM D94 describe the titration method: dissolve fat in excess KOH in ethanol, reflux, then back-titrate with HCl. The mg KOH consumed per gram of fat equals the saponification value.
How does saponification value relate to soap making?
In soap making, the saponification value tells you how much lye (NaOH) or KOH to use per gram of oil. For NaOH, divide the SV by the ratio of MW of KOH to NaOH (56.11 / 40.00 = 1.403). This is called the SAP value and is used to calculate lye amounts in recipes.
Official sources
- AOCS (American Oil Chemists Society): Official Methods (Cd 3-25 Saponification Value).
- NIST Chemistry WebBook: Molecular weight data for fatty acids.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.