SAP Value Calculator — Saponification Values
Look up and calculate saponification values for common soap-making oils.
Select the oil to look up its saponification value
NaOH for bar soap, KOH for liquid soap
Weight of oil to calculate lye for
How We Calculate This
How the Calculation Works
Each oil has a known NaOH SAP value (grams of NaOH to saponify 1 gram of oil). For KOH, the NaOH value is multiplied by 1.403.
Lye needed = oil weight (g) x SAP value. This is before any superfat adjustment. To apply superfat, multiply the result by (1 - superfat%).
Frequently Asked Questions
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Last updated: 2025-02-20
All calculations are estimates. Always verify quantities before purchasing materials.