This is a free soap calculator — no account needed to calculate.Add your oils and their percentages, set the total oil weight, superfat, and lye type, and it computes the exact lye (NaOH or KOH), the water, and a full quality profile for the bar you're designing.
Oils & butters
70%NaOH lye
91.9 g
Water
186.6 g
How the soap calculator works
Every oil needs a specific amount of lye to turn into soap — its SAP value. For each oil the calculator multiplies its weight by its SAP value, adds them up, then applies your superfat: lye = base lye × (1 − superfat/100). Water is derived from your lye concentration.
The quality profile
Hardness, cleansing, conditioning, bubbly, creamy, and longevity come from your oils' fatty-acid composition. Use them to balance a recipe: a lot of coconut lifts cleansing and bubbly but can dry the skin, while olive lifts conditioning but makes a softer bar. Iodine and INS hint at hardness and shelf life.
Safety first
Soap making uses lye (sodium or potassium hydroxide), a caustic chemical. Always add lye to water (never water to lye), wear eye protection and gloves, and double-check your numbers. The lye math and safety checks here are always free.
Save, scale, and sell
Calculating is free forever. Create a free account to save recipes, track ingredient inventory, and run production batches — or import an existing recipe from soapcalc.net, Soapee, or MMS in seconds.