Soap Recipe Calculator: Lye

Design better handmade soap formulas. Easily calculate NaOH/KOH, check fatty acids, fine-tune superfat, and preview hardness, lather, INS & cost in real time.

Design perfect soap recipes in seconds.

Soap Calculator is a professional, offline lye calculator designed for handmade soap makers and hobbyists who want precise measurements without complicated setups.

Choose your base oils, set your batch size, and instantly get the exact NaOH or KOH required. As you tweak your ingredients, watch your soap's hardness, cleansing, lather, INS scoring, and total cost update in real-time.

Core Tools & Features: Real-time evaluation, multi-dimensional scoring, 100% offline usage with local storage, flexible units, recipe saving & sharing, classic templates, and a built-in database of over 170 oils.

Basic features are free forever, with a one-time Pro unlock (no ads or subscriptions).