Soap Calculator

Want to Make Your Own Soap?

Whether you're a curious beginner or a budding artisan, understanding the science behind soap making is the first step to crafting beautiful, skin-loving bars at home.

What Is a Soap Calculator?

A soap calculator (also called a lye calculator) helps you determine the exact amounts of oils, lye (sodium hydroxide or potassium hydroxide), and water needed to create a balanced, safe soap recipe. Getting these ratios right is essential — too much lye can make soap harsh on skin, while too little can leave your soap greasy or soft.

How to Use a Soap Calculator

  1. Choose your oils — Different oils contribute different properties (e.g., coconut oil for lather, olive oil for conditioning).
  2. Enter your batch size — Decide how much soap you want to make.
  3. Select your lye type — NaOH for bar soap, KOH for liquid soap.
  4. Set your superfat level — A 5–8% superfat is recommended for a gentle, moisturizing bar.
  5. Calculate — The calculator will give you precise measurements for a safe, balanced recipe.

Try the Soap Calculator

Use the interactive calculator below, powered by LatherLogicLab.com:

If the calculator doesn't load above, you can visit it directly at LatherLogicLab.com.

A Note from Jask Beauty Essentials

At Jask Beauty, we craft every bar with intention — using botanicals, skin-loving oils, and small-batch care. If you're inspired to start your own soap-making journey, we hope this resource helps you get started with confidence.