Soap Lye Calculator

Calculate lye and water for cold process soap making.

Oil Weight (oz)

SAP Value (NaOH)

Superfat (%)

Water as % of Oils

Formula

Lye = Oil Weight x SAP Value x (1 - Superfat% / 100)

What is superfatting in soap making?

Superfatting leaves extra oil in soap for a moisturizing bar.

Can I substitute KOH for NaOH?

Yes, but KOH makes liquid soap. Multiply lye amount by 1.4.