Soap Making Calculator

Create Safe and Balanced Soap Recipes

⚠️ Safety First

  • Always wear protective gear (goggles, gloves)
  • Add lye to water, never water to lye
  • Work in a well-ventilated area
  • Keep vinegar nearby for neutralizing spills
  • Keep materials away from children and pets

Step 1: Choose Your Process

Different processes have different advantages:

  • Cold Process: Most customizable, longest cure (4-6 weeks)
  • Hot Process: Faster cure (1-2 weeks), rustic look
  • Melt and Pour: Easiest, no lye handling, ready immediately

Step 2: Set Batch Size

Recommended batch sizes:

  • Beginners: 16-32 ounces (makes 4-8 bars)
  • Small batch: 32-48 ounces (makes 8-12 bars)
  • Large batch: 64+ ounces (makes 16+ bars)

Step 3: Choose a Recipe or Create Your Own

Click any recipe button to automatically load it into the calculator. All recipes are tested and balanced for good soap properties.

Basic Beginner Recipe

  • Olive Oil: 60%
  • Coconut Oil: 25%
  • Palm Oil: 10%
  • Castor Oil: 5%

A gentle, well-balanced soap suitable for most skin types.

Extra Moisturizing

  • Olive Oil: 70%
  • Coconut Oil: 20%
  • Shea Butter: 5%
  • Castor Oil: 5%

Perfect for dry or sensitive skin.

Extra Cleansing

  • Olive Oil: 45%
  • Coconut Oil: 30%
  • Palm Oil: 20%
  • Castor Oil: 5%

Great for oily skin or kitchen soap.

Luxury Soap

  • Olive Oil: 40%
  • Coconut Oil: 25%
  • Shea Butter: 15%
  • Avocado Oil: 15%
  • Castor Oil: 5%

Rich, creamy lather with excellent skin conditioning.

Step 4: Oil Percentages

The percentages in the highlighted fields must add up to exactly 100%

Current total: 0%

Step 5: Advanced Settings

Super Fat Percentage

Super Fat is extra oil that doesn't react with lye, making a gentler soap. It:

  • Makes soap more moisturizing
  • Creates a milder bar
  • Provides skin-nourishing properties
%

Properties of selected super fat oil:

    Water Ratio

    The amount of water relative to oils:

    • Higher ratio = Softer soap, longer cure
    • Lower ratio = Harder soap, faster cure
    38% is standard. Lower = faster cure but harder to work with
    Essential oils: 0.5-3%, Fragrance oils: 2-6%

    Mixing Instructions

    Temperature Guidelines

      Curing Guidelines

      The Art and Science of Soap Making

      Understanding Soap Making Methods

      There are several methods for making soap, each with its own advantages:

      Choosing Your Oils

      Different oils contribute unique properties to your soap:

      Essential Oil Usage

      Essential oils add natural fragrance and potential therapeutic benefits:

      Curing and Storage

      Proper curing is crucial for quality soap:

      Frequently Asked Questions

      What is the difference between hot and cold process soap making?

      Cold process soap making involves mixing oils and lye at relatively low temperatures and allowing the soap to cure for 4-6 weeks. Hot process soap making applies external heat throughout the process, which speeds up saponification and results in a shorter cure time of 1-2 weeks. Both methods produce quality soap, but cold process generally allows for more intricate designs.

      Why is my soap not hardening properly?

      Soft soap can result from several factors: too much water in the recipe, insufficient hard oils (like coconut or palm), too high superfatting percentage, or inadequate cure time. Using this calculator helps ensure proper ratios for a firm bar of soap.

      What is superfatting and why is it important?

      Superfatting is the process of adding extra oils beyond what's needed for the lye reaction. This creates a milder, more moisturizing soap. A 5% superfat is standard for body soap, while facial soaps might use 6-8%. Lower superfat (1-3%) is common for laundry soap.

      How do I know if my soap is safe to use?

      Safe soap should have no excess lye (properly calculated using this calculator), be fully saponified (proper cure time), and pH tested if desired (should be between 8-10). Always use proper safety equipment when making soap and follow recommended cure times.

      Can I substitute oils in a recipe?

      Yes, but you must recalculate the lye amount as different oils have different saponification values. Use this calculator when making substitutions to ensure proper lye ratios. Try to substitute oils with similar properties for best results.