Cold-process NaOH and water amounts for your oil blend — with superfat % for a balanced or extra-moisturizing bar.
Lye (NaOH/KOH) is caustic and generates heat when mixed with water. Always wear safety glasses and gloves, work in a ventilated space, and add lye to water — never the reverse.
Total oil weight
800.0 g
NaOH amount
110.58 g
Water amount
264.0 g
Total batch weight
1,174.6 g
Every oil has a saponification (SAP) value — the grams of lye it takes to fully convert 1 g of that oil into soap. Multiply each oil’s weight by its SAP value, sum the results, and subtract the superfat percentage to leave unreacted oil in the bar for conditioning.
Switch to KOH for liquid soap paste — KOH is weaker than NaOH, so the required amount is 1.403× the NaOH figure. Water at 33% of oil weight is a standard workable ratio; drop to 28% for a water discount and faster trace.
NaOH_g = Σ(oil_g × SAP) × (1 − superfat ÷ 100)
KOH_g = NaOH_g × 1.403
water_g = total_oil_g × (water% ÷ 100)