Lye Calculator
Formulate cold process, hot process, or liquid soap. Pick your oils, set your superfat, and get exact lye and water amounts — plus a prediction of how your bar will perform.
Safety first: Lye (sodium hydroxide / potassium hydroxide) is caustic. Always wear gloves and eye protection, add lye to water (never water to lye), and work in a ventilated area. This calculator is a formulation aid — always double-check critical recipes.
Your Recipe
4.7 g
Lye (NaOH)
9.6 g
Distilled water
46.3 g
Total batch weight
Oil Breakdown
| Oil | % | Weight |
|---|---|---|
| Babassu oil | 50.0% | 16.0 g |
| Olive oil | 30.0% | 9.6 g |
| Cocoa butter | 20.0% | 6.4 g |
Predicted Bar Qualities
Hardness (29–54)54
Cleansing (12–22)31
Conditioning (44–69)40
Bubbly lather (14–46)31
Creamy lather (16–48)24
Iodine (41–70)41
INS (136–165)114
Green = within the typical desirable range. These are estimates based on fatty acid profiles — actual results vary with technique, cure time, and additives.
Formulation tip: Balance cleansing oils (coconut, palm kernel, babassu) with conditioning oils (olive, shea, avocado). Castor oil at 5–10% boosts lather. Cure cold process bars 4–6 weeks before use.
