Lye calculator
Free, no account needed. Lye, water, and bar properties update as you type. To save recipes, add your own oils, plan batches, and track inventory, sign up for a free account.
Safety
Before you use the lye calculator
- Sodium hydroxide (NaOH) and potassium hydroxide (KOH) are caustic. They can burn skin and cause blindness. Wear goggles, gloves, and long sleeves, work with good ventilation, and keep children and pets away.
- Always add lye to water, never water to lye. The solution gets very hot.
- The calculator uses typical published values. Your oils, lye purity, and scale can differ. Check every lye and water amount yourself, with a second calculator or by hand, before you mix anything.
- You are responsible for your recipes, how you make them, and the products you sell.